drm/amd/powerplay: refine vce dpm update code on Cz.

drm/amd/powerplay: refine vce dpm update code on Cz.

[ Upstream commit ab8db87b8256e13a62f10af1d32f5fc233c398cc ]

Program HardMin based on the vce_arbiter.ecclk
if ecclk is 0, disable ECLK DPM 0. Otherwise VCE
could hang if switching SCLK from DPM 0 to 6/7

Signed-off-by: Rex Zhu <Rex.Zhu@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>