Instead of using hardcoded values, use enumerations for mailbox command
and sub commands.
Signed-off-by: NRaju Rangoju <Raju.Rangoju@amd.com>
Acked-by: NTom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>