The IPMI driver unconditionally instructed the BMC not automatically
clear boot flag valid bit if Chassis Control command not received within
60-second timeout (countdown restarts when a Chassis Control command is
received). Some BMCs do not support setting this. Sending the command
aborts the node boot.
A new driver option ``ipmi_disable_timeout`` is added to bypass
sending this command.
Change-Id: I1dda3cf3e4b7b888ed9d8931c8ede3a918dd01f4
Story: 2004266