drm/amdgpu: enable mmhub clock gating for navi12

enables mmhub medium grained clock gating and memory light sleep

Signed-off-by: Xiaojie Yuan <xiaojie.yuan@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
1 file changed