For some reason we run into an use case where a BO is already pinned
into GTT, but should be pinned into VRAM|GTT again.

Handle that case gracefully as well.
Reviewed-by: NShashank Sharma <Shashank.sharma@amd.com>
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NChristian König <christian.koenig@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org