LE: Add API to set scan interval and window (1/4)

Delete client_if from scan api's
Change-Id: If24cb134ae7204de69c8c89664ce34f9d59da76a
diff --git a/include/hardware/bt_gatt_client.h b/include/hardware/bt_gatt_client.h
index baed4bd..abd2e86 100644
--- a/include/hardware/bt_gatt_client.h
+++ b/include/hardware/bt_gatt_client.h
@@ -195,7 +195,7 @@
     bt_status_t (*unregister_client)(int client_if );
 
     /** Start or stop LE device scanning */
-    bt_status_t (*scan)( int client_if, bool start );
+    bt_status_t (*scan)( bool start );
 
     /** Create a connection to a remote LE or dual-mode device */
     bt_status_t (*connect)( int client_if, const bt_bdaddr_t *bd_addr,
@@ -304,6 +304,9 @@
     /** Configure the MTU for a given connection */
     bt_status_t (*configure_mtu)(int conn_id, int mtu);
 
+    /** Sets the LE scan interval and window in units of N*0.625 msec */
+    bt_status_t (*set_scan_parameters)(int scan_interval, int scan_window);
+
     /** Test mode interface */
     bt_status_t (*test_command)( int command, btgatt_test_params_t* params);