drm/amdkfd: Remove unused field from struct qcm_process_device

Signed-off-by: Oded Gabbay <oded.gabbay@amd.com>
Reviewed-by: Ben Goz <ben.goz@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdkfd/kfd_priv.h

@@ -378,8 +378,6 @@ struct qcm_process_device {
 	/* The Device Queue Manager that owns this data */
 	struct device_queue_manager *dqm;
 	struct process_queue_manager *pqm;
-	/* Device Queue Manager lock */
-	struct mutex *lock;
 	/* Queues list */
 	struct list_head queues_list;
 	struct list_head priv_queue_list;