mei: add a handler that waits for notification on event

mei_cl_notify_get is to be called by a host client
to wait, receive, and ack the event notification.

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/misc/mei/mei_dev.h

@@ -235,6 +235,7 @@ struct mei_cl_cb {
  * @tx_wait: wait queue for tx completion
  * @rx_wait: wait queue for rx completion
  * @wait:  wait queue for management operation
+ * @ev_wait: notification wait queue
  * @status: connection status
  * @me_cl: fw client connected
  * @host_client_id: host id
@@ -256,6 +257,7 @@ struct mei_cl {
 	wait_queue_head_t tx_wait;
 	wait_queue_head_t rx_wait;
 	wait_queue_head_t wait;
+	wait_queue_head_t ev_wait;
 	int status;
 	struct mei_me_client *me_cl;
 	u8 host_client_id;