drm/amd/powerplay: add interface to check fw version (v2)

This patch adds interface to check fw version for smu.
It's to send msg GetDriverIfVersion to check if the return value is equal with
DRIVER_IF_VERSION of smc header.

v2: add detailed info to describe this function

Signed-off-by: Huang Rui <ray.huang@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>