drm/amdgpu: don't try to move pinned BOs

[ Upstream commit 6edc6910ba4cd6eab309263539c8f09b8ad772bf ]

Never try to move pinned BOs during CS.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Michel Dänzer <michel.daenzer@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>