bmc-reboot: add pinhole reset reason

Some systems have a physical mechanism on them to force a reboot of the
BMC. One common mechanism for this is a pinhole. The user utilizes a
round, thin piece of metal (commonly a paper clip) to trigger this
reset.

The use of the pinhole reset is usually utilized to force a reboot of
an unresponsive BMC. BMC firmware, when it comes back from the reboot,
may want to do some special handling for this scenario.

Some systems, like the IBM p10bmc machines, have some logic in the
hardware to set a GPIO so that BMC firmware will have a mechanism to
know if the reboot cause was the result of a pinhole reset. IBM systems
would like to add some software logic around this. For example, if a
pinhole reset was done, the firmware will not run its auto power on
functions. If a user has force reset a system, they do not want firmware
trying to auto power on the machine.

The design on this can be found here:
  https://gerrit.openbmc-project.xyz/c/openbmc/docs/+/47816

Signed-off-by: Andrew Geissler <geissonator@yahoo.com>
Change-Id: Id8f0e5b8da708ec82d13a89013e19692ef5959b8
diff --git a/yaml/xyz/openbmc_project/State/BMC.interface.yaml b/yaml/xyz/openbmc_project/State/BMC.interface.yaml
index fd04397..62d55e2 100644
--- a/yaml/xyz/openbmc_project/State/BMC.interface.yaml
+++ b/yaml/xyz/openbmc_project/State/BMC.interface.yaml
@@ -72,6 +72,9 @@
        - name: 'POR'
          description: >
            Last reboot is caused by Power-On-Reset
+       - name: 'PinholeReset'
+         description: >
+           Last reboot is caused by pinhole reset
        - name: 'Watchdog'
          description: >
            Last reboot is caused by Watchdog