i2c-mux-gpio: Fix GPIO request flag issue

When requesting GPIO, the GPIOD_IS_OUT is missed in flag, so the GPIO
is set the input mode not output and cause mux not work.
Signed-off-by: NYe Li <ye.li@nxp.com>

drivers/i2c/muxes/i2c-mux-gpio.c

@@ -106,7 +106,7 @@ static int i2c_mux_gpio_probe(struct udevice *dev)
 	}
 
 	ret = gpio_request_list_by_name(dev, "mux-gpios", gpios, mux->n_gpios,
-					GPIOD_IS_OUT_ACTIVE);
+					GPIOD_IS_OUT | GPIOD_IS_OUT_ACTIVE);
 	if (ret <= 0) {
 		dev_err(dev, "Failed to request mux-gpios\n");
 		return ret;