drm/radeon: add Mullins UVD support.

Has same version of UVD as other CIK parts.
Signed-off-by: NSamuel Li <samuel.li@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NChristian König <christian.koenig@amd.com>

drivers/gpu/drm/radeon/radeon_uvd.c

@@ -99,6 +99,7 @@ int radeon_uvd_init(struct radeon_device *rdev)
 	case CHIP_KABINI:
 	case CHIP_KAVERI:
 	case CHIP_HAWAII:
+	case CHIP_MULLINS:
 		fw_name = FIRMWARE_BONAIRE;
 		break;