platform: add Radxa ROCK 5B platform support

Signed-off-by: Nascs <nascs@radxa.com>

include/arm/radxa_rock_5b.h

@@ -0,0 +1,30 @@
+/*
+ * Author: Nascs <nascs@radxa.com>
+ * Copyright (c) Radxa Limited.
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#pragma once
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include "mraa_internal.h"
+
+#define MRAA_RADXA_ROCK_5B_GPIO_COUNT 26
+#define MRAA_RADXA_ROCK_5B_I2C_COUNT  4
+#define MRAA_RADXA_ROCK_5B_SPI_COUNT  2 
+#define MRAA_RADXA_ROCK_5B_UART_COUNT 4
+#define MRAA_RADXA_ROCK_5B_PWM_COUNT  10
+#define MRAA_RADXA_ROCK_5B_AIO_COUNT  1
+#define MRAA_RADXA_ROCK_5B_PIN_COUNT  40
+#define PLATFORM_NAME_RADXA_ROCK_5B   "Radxa ROCK 5B"
+
+mraa_board_t *
+        mraa_radxa_rock_5b();
+
+#ifdef __cplusplus
+}
+#endif