kernel: tune 24kc instead of 34kc for mips32r2

GCC generates the same code for 24kc and 34kc. Since we have
converted all 34kc targets to the 24kc, it's better to switch
kernel -mtune to 24kc to avoid confusing developers.

Signed-off-by: Shiji Yang <yangshiji66@outlook.com>
Link: openwrt/openwrt#22703
Signed-off-by: Robert Marko <robimarko@gmail.com>

Author: DragonBluep

target/linux/generic/pending-6.12/308-mips32r2_tune.patch

@@ -1,5 +1,5 @@
 From: Felix Fietkau <nbd@nbd.name>
-Subject: kernel: add -mtune=34kc to MIPS CFLAGS when building for mips32r2
+Subject: kernel: add -mtune=24kc to MIPS CFLAGS when building for mips32r2
 
 This provides a good tradeoff across at least 24Kc-74Kc, while also
 producing smaller code.
@@ -16,7 +16,7 @@ Signed-off-by: Felix Fietkau <nbd@nbd.name>
  cflags-$(CONFIG_CPU_TX49XX)	+= $(call cc-option,-march=r4600,-march=mips3) -Wa,--trap
  cflags-$(CONFIG_CPU_MIPS32_R1)	+= -march=mips32 -Wa,--trap
 -cflags-$(CONFIG_CPU_MIPS32_R2)	+= -march=mips32r2 -Wa,--trap
-+cflags-$(CONFIG_CPU_MIPS32_R2)	+= -march=mips32r2 -mtune=34kc -Wa,--trap
++cflags-$(CONFIG_CPU_MIPS32_R2)	+= -march=mips32r2 -mtune=24kc -Wa,--trap
  cflags-$(CONFIG_CPU_MIPS32_R5)	+= -march=mips32r5 -Wa,--trap -modd-spreg
  cflags-$(CONFIG_CPU_MIPS32_R6)	+= -march=mips32r6 -Wa,--trap -modd-spreg
  cflags-$(CONFIG_CPU_MIPS64_R1)	+= -march=mips64 -Wa,--trap

target/linux/generic/pending-6.18/308-mips32r2_tune.patch

@@ -1,5 +1,5 @@
 From: Felix Fietkau <nbd@nbd.name>
-Subject: kernel: add -mtune=34kc to MIPS CFLAGS when building for mips32r2
+Subject: kernel: add -mtune=24kc to MIPS CFLAGS when building for mips32r2
 
 This provides a good tradeoff across at least 24Kc-74Kc, while also
 producing smaller code.
@@ -16,7 +16,7 @@ Signed-off-by: Felix Fietkau <nbd@nbd.name>
  cflags-$(CONFIG_CPU_TX49XX)	+= $(call cc-option,-march=r4600,-march=mips3) -Wa,--trap
  cflags-$(CONFIG_CPU_MIPS32_R1)	+= -march=mips32 -Wa,--trap
 -cflags-$(CONFIG_CPU_MIPS32_R2)	+= -march=mips32r2 -Wa,--trap
-+cflags-$(CONFIG_CPU_MIPS32_R2)	+= -march=mips32r2 -mtune=34kc -Wa,--trap
++cflags-$(CONFIG_CPU_MIPS32_R2)	+= -march=mips32r2 -mtune=24kc -Wa,--trap
  cflags-$(CONFIG_CPU_MIPS32_R5)	+= -march=mips32r5 -Wa,--trap -modd-spreg
  cflags-$(CONFIG_CPU_MIPS32_R6)	+= -march=mips32r6 -Wa,--trap -modd-spreg
  cflags-$(CONFIG_CPU_MIPS64_R1)	+= -march=mips64 -Wa,--trap

target/linux/realtek/patches-6.12/308-tune-switch-4kec.patch

@@ -2,7 +2,7 @@ From: Markus Stockhausen <markus.stockhausen@gmx.de>
 Date: Fri, 13 Jun 2025 20:25:37 +0100
 Subject: [PATCH] realtek: set mtune 4kec for RTL838x targets
 
-Generic patches will always force the gcc kernel tuning to 34kc. With RTL838x 
+Generic patches will always force the gcc kernel tuning to 24kc. With RTL838x 
 being only 4kec this does not harm but is not right. Match the tuning properly.
 
 Signed-off-by: Markus Stockhausen <markus.stockhausen@gmx.de>
@@ -13,10 +13,10 @@ Signed-off-by: Markus Stockhausen <markus.stockhausen@gmx.de>
 @@ -164,6 +164,11 @@ cflags-$(CONFIG_CPU_R4X00)	+= $(call cc-
  cflags-$(CONFIG_CPU_TX49XX)	+= $(call cc-option,-march=r4600,-march=mips3) -Wa,--trap
  cflags-$(CONFIG_CPU_MIPS32_R1)	+= -march=mips32 -Wa,--trap
- cflags-$(CONFIG_CPU_MIPS32_R2)	+= -march=mips32r2 -mtune=34kc -Wa,--trap
+ cflags-$(CONFIG_CPU_MIPS32_R2)	+= -march=mips32r2 -mtune=24kc -Wa,--trap
 +
 +#ifdef CONFIG_RTL838X
-+cflags-$(CONFIG_CPU_MIPS32_R2) := $(subst 34kc,4kec,$(cflags-$(CONFIG_CPU_MIPS32_R2)))
++cflags-$(CONFIG_CPU_MIPS32_R2) := $(subst 24kc,4kec,$(cflags-$(CONFIG_CPU_MIPS32_R2)))
 +#endif
 +
  cflags-$(CONFIG_CPU_MIPS32_R5)	+= -march=mips32r5 -Wa,--trap -modd-spreg

target/linux/realtek/patches-6.18/308-tune-switch-4kec.patch

@@ -2,7 +2,7 @@ From: Markus Stockhausen <markus.stockhausen@gmx.de>
 Date: Fri, 13 Jun 2025 20:25:37 +0100
 Subject: [PATCH] realtek: set mtune 4kec for RTL838x targets
 
-Generic patches will always force the gcc kernel tuning to 34kc. With RTL838x 
+Generic patches will always force the gcc kernel tuning to 24kc. With RTL838x 
 being only 4kec this does not harm but is not right. Match the tuning properly.
 
 Signed-off-by: Markus Stockhausen <markus.stockhausen@gmx.de>
@@ -13,10 +13,10 @@ Signed-off-by: Markus Stockhausen <markus.stockhausen@gmx.de>
 @@ -160,6 +160,11 @@ cflags-$(CONFIG_CPU_R4X00)	+= $(call cc-
  cflags-$(CONFIG_CPU_TX49XX)	+= $(call cc-option,-march=r4600,-march=mips3) -Wa,--trap
  cflags-$(CONFIG_CPU_MIPS32_R1)	+= -march=mips32 -Wa,--trap
- cflags-$(CONFIG_CPU_MIPS32_R2)	+= -march=mips32r2 -mtune=34kc -Wa,--trap
+ cflags-$(CONFIG_CPU_MIPS32_R2)	+= -march=mips32r2 -mtune=24kc -Wa,--trap
 +
 +#ifdef CONFIG_RTL838X
-+cflags-$(CONFIG_CPU_MIPS32_R2) := $(subst 34kc,4kec,$(cflags-$(CONFIG_CPU_MIPS32_R2)))
++cflags-$(CONFIG_CPU_MIPS32_R2) := $(subst 24kc,4kec,$(cflags-$(CONFIG_CPU_MIPS32_R2)))
 +#endif
 +
  cflags-$(CONFIG_CPU_MIPS32_R5)	+= -march=mips32r5 -Wa,--trap -modd-spreg