freertos: release the generic version source code

freertos runs on the second core (small one) of the CPU

freertos/cvitek/driver/gpio/include/gpio.h

@@ -0,0 +1,19 @@
+#ifndef __GPIO_H__
+#define __GPIO_H__
+
+#include <stddef.h>
+#include <stdint.h>
+
+#define CVI_GPIOA_BASE		0x03020000
+#define CVI_GPIOB_BASE		0x03021000
+#define CVI_GPIOC_BASE		0x03022000
+#define CVI_GPIOD_BASE		0x03023000
+
+enum of_gpio_flags {
+	OF_GPIO_ACTIVE_LOW  = 0x1
+};
+
+int gpio_is_valid(int pin);
+void gpio_direction_output(int pin, int val);
+
+#endif