drm/amdgpu: disable GFX RAS by default

GFX RAS has not been stablized yet. disable GFX ras until
it is fully funcitonal.
Signed-off-by: Hawking Zhang <Hawking.Zhang@amd.com>
Reviewed-by: Feifei Xu <Feifei.Xu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -148,7 +148,7 @@ struct amdgpu_mgpu_info mgpu_info = {
 	.mutex = __MUTEX_INITIALIZER(mgpu_info.mutex),
 };
 int amdgpu_ras_enable = -1;
-uint amdgpu_ras_mask = 0xffffffff;
+uint amdgpu_ras_mask = 0xfffffffb;
 
 /**
  * DOC: vramlimit (int)