drm/amd/pm: Notify PMFW about driver unload cases

On SMU v13.0.6 APUs, FW will need to take some actions if driver is going
to halt RLC. Notify PMFW that driver is not going to manage device so
that FW takes care of the required actions.

Signed-off-by: Lijo Lazar <lijo.lazar@amd.com>
Reviewed-by: Le Ma <le.ma@amd.com>
Reviewed-by: Asad Kamal <asad.kamal@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>