FROMGIT: drm/amdgpu: Power down acp if board uses AZ (v2)

if board uses AZ rather than ACP, we power down acp
through smu to save power.

v2: handle S3/S4 and hw_fini (Alex)

Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Rex Zhu <Rex.Zhu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

(cherry picked from commit be2d6aa5
git://anongit.freedesktop.org/drm/drm of origin/drm-next branch)

BUG=b:117711307
TEST=Build & Boot on Careena

Change-Id: Icb87e99ddb1a8ccb9f276f8f2f69813f3afc521e
Reviewed-on: https://chromium-review.googlesource.com/1294552


Commit-Ready: ChromeOS CL Exonerator Bot <chromiumos-cl-exonerator@appspot.gserviceaccount.com>
Tested-by: Hang Zhou <hang.zhou@amd.corp-partner.google.com>
Reviewed-by: Daniel Kurtz <djkurtz@chromium.org>