Add missing SCMI v3.1 command definitions

Many testcases covers the scenario in which invalid SCMI command IDs are
used: these are generally defined as one-off the last valid known command
ID; now that SCMIv3.1 spec is published all valid v3.1. commands, for all
the protocols supported by this suite, should be enumerated properly to
avoid using by mistake a valid command ID as an invalid one in case the
SCMI backend server under test already supported it.

Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>