Some buffers (UVD/VM page tables) must be placed in VRAM,
but the byte restriction for moving buffers didn't took this
into account.

v2: keep closer to the original code
Signed-off-by: NChristian König <christian.koenig@amd.com>
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Reviewed-by: NMarek Olšák <marek.olsak@amd.com>