[BSP] Add GPIO driver for STM32F4

bsp/stm32f40x/drivers/gpio.h

@@ -0,0 +1,19 @@
+/*
+ * File      : gpio.h
+ * This file is part of RT-Thread RTOS
+ * COPYRIGHT (C) 2015, RT-Thread Development Team
+ *
+ * The license and distribution terms for this file may be
+ * found in the file LICENSE in this distribution or at
+ * http://www.rt-thread.org/license/LICENSE
+ *
+ * Change Logs:
+ * Date           Author       Notes
+ * 2015-01-05     Bernard      the first version
+ */
+#ifndef GPIO_H__
+#define GPIO_H__
+
+int stm32_hw_pin_init(void);
+
+#endif