drm/amdgpu: disable SDMA page queue on Vega20

Since we see driver loading failure on Vega20. Keep it
disabled until it's ready.
Signed-off-by: Evan Quan <evan.quan@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/sdma_v4_0.c

@@ -1464,6 +1464,7 @@ static int sdma_v4_0_early_init(void *handle)
 		adev->sdma.has_page_queue = false;
 	} else {
 		adev->sdma.num_instances = 2;
+		if (adev->asic_type != CHIP_VEGA20)
 			adev->sdma.has_page_queue = true;
 	}