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/commands.hpp b/commands.hpp
index 86a2650..7c8858d 100644
--- a/commands.hpp
+++ b/commands.hpp
@@ -55,6 +55,8 @@
     SysPCIeSlotBifurcation = 15,
     // The Sys get BMC Mode command
     SysGetBmcMode = 16,
+    // The Sys Linux Boot Done command
+    SysLinuxBootDone = 17,
 };
 
 } // namespace ipmi