drm/amd/pm: Fix missing thermal throttler status

[ Upstream commit b0f4d663 ]

On aldebaran, when thermal throttling happens due to excessive GPU
temperature, the reason for throttling event is missed in warning
message. This patch fixes it.

Signed-off-by: Lijo Lazar <lijo.lazar@amd.com>
Reviewed-by: Yang Wang <kevinyang.wang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>