drm/amdgpu: enable sdma clock gating for Arcturus

Init sdma MGCG/LS flag
Signed-off-by: Le Ma <le.ma@amd.com>
Reviewed-by: Feifei Xu <Feifei.Xu@amd.com>
Reviewed-by: Kenneth Feng <kenneth.feng@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/soc15.c

@@ -1124,7 +1124,9 @@ static int soc15_common_early_init(void *handle)
 			AMD_CG_SUPPORT_GFX_CGCG |
 			AMD_CG_SUPPORT_GFX_CGLS |
 			AMD_CG_SUPPORT_HDP_MGCG |
-			AMD_CG_SUPPORT_HDP_LS;
+			AMD_CG_SUPPORT_HDP_LS |
+			AMD_CG_SUPPORT_SDMA_MGCG |
+			AMD_CG_SUPPORT_SDMA_LS;
 		adev->pg_flags = 0;
 		adev->external_rev_id = adev->rev_id + 0x32;
 		break;