TP-Link TL-WR703n增加一个GPIO控制按钮

https://forum.openwrt.org/viewtopic.php?id=39811

修改target/linux/ar71xx/files/arch/mips/ath79/mach-tl-wr703n.c

#define TL_WR703N_GPIO_LED_SYSTEM    27
#define SENSOR_BTN_29            29

static struct gpio_keys_button tl_wr703n_gpio_keys[] __initdata = {
    {
        .desc        = "reset",
        .type        = EV_KEY,
        .code        = KEY_RESTART,
        .debounce_interval = TL_WR703N_KEYS_DEBOUNCE_INTERVAL,
        .gpio        = TL_WR703N_GPIO_BTN_RESET,
        .active_low    = 0,
    },{
        .desc        = "sensor",
        .type        = EV_KEY,
        .code        = BTN_1,
        .debounce_interval = TL_WR703N_KEYS_DEBOUNCE_INTERVAL,
        .gpio        = SENSOR_BTN_29,
        .active_low    = 1,
    }
};