drm/amdkfd: unmap VMID<-->PASID when relesing VMID (non-HWS)

This patch fixes a bug where deallocate_vmid() didn't actually unmap the
VMID<-->PASID mapping (in the registers).
That can cause undefined behavior.

This bug only occurs in non-HWS mode.
Signed-off-by: Ben Goz <ben.goz@amd.com>
Signed-off-by: Oded Gabbay <oded.gabbay@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c

@@ -161,6 +161,9 @@ static void deallocate_vmid(struct device_queue_manager *dqm,
 {
 	int bit = qpd->vmid - KFD_VMID_START_OFFSET;
 
+	/* Release the vmid mapping */
+	set_pasid_vmid_mapping(dqm, 0, qpd->vmid);
+
 	set_bit(bit, (unsigned long *)&dqm->vmid_bitmap);
 	qpd->vmid = 0;
 	q->properties.vmid = 0;