add raspi2 and raspi3 BSP

bsp/raspberry-pi/raspi3-32/driver/drv_timer.h

@@ -0,0 +1,27 @@
+/*
+ * Copyright (c) 2006-2019, RT-Thread Development Team
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Change Logs:
+ * Date           Author         Notes
+ * 2019-07-29     zdzn           first version
+ */
+#ifndef __DRV_TIMER_H__
+#define __DRV_TIMER_H__
+
+#include <rtthread.h>
+#include <rtdevice.h>
+
+#include "board.h"
+
+typedef struct rt_systimer_device
+{
+    int  timer_id;
+    rt_uint32_t cnt;
+} rt_systimer_t;
+
+int rt_hw_systimer_init(void);
+
+
+#endif