drm/amdkfd: Stop using GFP_NOIO explicitly

This is no longer needed with the memalloc_nofs_save/restore in
dqm_lock/unlock.

Signed-off-by: Felix Kuehling <Felix.Kuehling@amd.com>
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>