drm/amdgpu: Disable baco dummy mode

On aldebaran, BACO dummy mode may be enabled during reset. Disable
it during resume.

Signed-off-by: Lijo Lazar <lijo.lazar@amd.com>
Reviewed-by: Hawking Zhang <Hawking.Zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>