GattClient: remove deprecated onDataWrite

Author: LDong-Arm

features/FEATURE_BLE/ble/GattClient.h

@@ -525,25 +525,6 @@ class GattClient : public StaticInterface<Impl, GattClient> {
         return onDataWriteCallbackChain;
     }
 
-    /**
-     * Register an attribute write event handler.
-     *
-     * @param[in] callback Event handler being registered.
-     *
-     * @note It is possible to remove registered handlers using
-     * onDataWritten().detach(callbackToRemove).
-     *
-     * @note Write commands (issued using writeWoResponse) don't generate a
-     * response.
-     *
-     * @deprecated Use GattServer::onDataWritten().
-     */
-    MBED_DEPRECATED("Use GattServer::onDataWritten()")
-    void onDataWrite(WriteCallback_t callback)
-    {
-        onDataWritten(callback);
-    }
-
     /**
      * Register a service discovery termination event handler.
      *