freertos: release the generic version source code

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

freertos/cvitek/driver/gpio/src/gpio.c

@@ -0,0 +1,49 @@
+#include <stdio.h>
+#ifdef RUN_IN_SRAM
+#include "system_common.h"
+#endif
+
+#include "mmio.h"
+#include "gpio.h"
+
+
+int gpio_is_valid(int pin)
+{
+	switch ((pin >> 8)) {
+		case 0xA:
+		case 0xB:
+		case 0xC:
+		case 0xD:
+			return 1;
+		default:
+			return 0;
+	}
+}
+
+void gpio_direction_output(int pin, int val)
+{
+	uint32_t gpio_base;
+
+	switch ((pin >> 8)) {
+		case 0xB:
+			gpio_base = CVI_GPIOB_BASE;
+			break;
+		case 0xC:
+			gpio_base = CVI_GPIOC_BASE;
+			break;
+		case 0xD:
+			gpio_base = CVI_GPIOD_BASE;
+			break;
+		case 0xA:
+			gpio_base = CVI_GPIOA_BASE;
+			break;
+		default:
+			return;
+	}
+
+	pin &= 0xff;
+	// GPIO_OE
+	mmio_write_32(gpio_base + 4, 1 << pin);
+	// GPIO_O
+	mmio_write_32(gpio_base, val << pin);
+}