drm/amd/pm: correct smu 13.0.0/7 mp1 state setup

Only PP_MP1_STATE_UNLOAD is supported for now. For other mp1 state, we
should just ignore it. Otherwise, there will be errors coming out.

Signed-off-by: Evan Quan <evan.quan@amd.com>
Reviewed-by: Hawking Zhang <Hawking.Zhang@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>