Add support for injecting, monitoring, and reporting on tofino's error interrupts

[Nieuwejaar]

We can see dendrite detecting and reporting errors in response to tofino interrupts:

00:11:00.686Z DEBG dpd:   group stat for shadow TCAM ECC pipe: 1 mau: 19: 256
    unit = interrupt monitor
00:11:00.686Z ERRO dpd: single-bit error on TCAM [pipe: 1, mau: 19].  row: 4  addr: 0x16
    unit = interrupt monitor
00:11:00.686Z DEBG dpd: handled interrupt [pipe: 1, mau: 19]
    unit = interrupt monitor
00:11:08.464Z DEBG dpd:   group stat for shadow PCIe Errors: 32
    unit = interrupt monitor
00:11:08.465Z ERRO dpd: CPU request timeout detected
    unit = interrupt monitor
00:11:08.465Z DEBG dpd: handled interrupt PcieCpuTimeout

These two errors were triggered by the new intr tool running in the global zone:

BRM42220007 # ./intr inject tcam ecc -p 1 -m 19 -r 4 -a 22
writing sbe reg: TcamSbeErrlog(BitSet([22, 0, 0, 0])) at 0x59c0e10
writing inject reg IntrInjectMauTcamArray(BitSet([0, 1, 0, 0])) at 0x59c0f20
BRM42220007 # ./intr inject pcie ct
writing pci injection register PcieIntrInj(BitSet([32, 0, 0, 0])) at 0x14c
BRM42220007 #