feat(rmm-eac4): Add support for new RMI_VERSION cmd

This patch adds the necessary support for the new RMI_VERSION
command as mentioned EAC4 specification.

Signed-off-by: Soby Mathew <soby.mathew@arm.com>
Change-Id: I4629357b42d05d291fd81aaea97edf0a0c4518f5
6 files changed