Add IPMI OEM command LinuxBootDone

Add a new OEM command for LinuxBoot to notify the BMC when it is about
to kexec into the OS. This is intended to give the BMC a chance to
prepare for an untrusted OS, e.g. disable any interfaces it doesn't want
the OS to have access to.

Tested:
Exercised the new OEM command using ipmitool
$ ipmitool raw 0x2e 0x32 0x79 0x2b 0x00 0x11
  79 2b 00 11

Change-Id: Ica76d77cdde48cebfbced32d8e7e860b559074e8
Signed-off-by: John Wedig <johnwedig@google.com>
diff --git a/test/handler_mock.hpp b/test/handler_mock.hpp
index 9e9b71e..f62564e 100644
--- a/test/handler_mock.hpp
+++ b/test/handler_mock.hpp
@@ -63,6 +63,7 @@
                 (const, override));
     MOCK_METHOD(std::vector<uint8_t>, pcieBifurcation, (uint8_t), (override));
     MOCK_METHOD(uint8_t, getBmcMode, (), (override));
+    MOCK_METHOD(void, linuxBootDone, (), (const, override));
 };
 
 } // namespace ipmi