drm/radeon: add Mullins dpm support.

Generic dpm support similar to Kabini. Mullins specific features
will be worked on later.

Signed-off-by: Samuel Li <samuel.li@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Christian König <christian.koenig@amd.com>
diff --git a/drivers/gpu/drm/radeon/radeon_pm.c b/drivers/gpu/drm/radeon/radeon_pm.c
index 6fac8ef..f30b842 100644
--- a/drivers/gpu/drm/radeon/radeon_pm.c
+++ b/drivers/gpu/drm/radeon/radeon_pm.c
@@ -1300,6 +1300,7 @@
 	case CHIP_KABINI:
 	case CHIP_KAVERI:
 	case CHIP_HAWAII:
+	case CHIP_MULLINS:
 		/* DPM requires the RLC, RV770+ dGPU requires SMC */
 		if (!rdev->rlc_fw)
 			rdev->pm.pm_method = PM_METHOD_PROFILE;