drm/qxl: clean up qxl_bo_move_notify

Remove the unused evict parameter and drop swapping bo->mem.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210315191432.153826-1-christian.koenig@amd.com