meta-facebook: santabarbara: monitor SWB_PWR_FAULT_N PowerRailFault

Decode SWB CPLD fault register on rising edge and log PowerRailFault
with the affected rail name. Resolve the log entry on falling edge.

Persist log entry path to /var/lib/phosphor-gpio-monitor/ so it
survives BMC reboot and can be resolved via INIT_LOW after AC cycle.

Tested on Santabarbara platform:
```
root@bmc:~# systemctl start swb-pwr-fault-assert.service
root@bmc:~# mfg-tool log-display
    "64": {
        "message": "xyz.openbmc_project.State.Power.PowerRailFault",
        "additional_data": {
            "FAILURE_DATA": "SWB_CPLD_PWR_FAULT - [P0V81_PEX0_Power_fault]",
            ...
        },
        "resolved": false,
        ...
    }

root@bmc:~# mfg-tool power-control -p 0 -a cycle -s standby
root@bmc:~# mfg-tool log-display
    "64": {
        "message": "xyz.openbmc_project.State.Power.PowerRailFault",
        "additional_data": {
            "FAILURE_DATA": "SWB_CPLD_PWR_FAULT - [P0V81_PEX0_Power_fault]",
            ...
        },
        "resolved": true,
        ...
    }
```

Change-Id: Ifadcd11b783a925a06f2dd5685598b787253848e
Signed-off-by: Freddie Jheng <Freddie.Jheng@quantatw.com>

0 files changed, 0 insertions, 0 deletions