drm/amd/pm: add missing NotifyPowerSource message mapping for SMU13.0.7

Otherwise, the power source switching will fail due to message
unavailable.

Fixes: bf482326

 ("drm/amd/pm: fix possible power mode mismatch between driver and PMFW")
Signed-off-by: Evan Quan <evan.quan@amd.com>
Reviewed-by: Guchun Chen <guchun.chen@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org