soc: fsl: qe: remove set but not used variable 'mm_gc'

drivers/soc/fsl/qe/gpio.c: In function qe_pin_request:
drivers/soc/fsl/qe/gpio.c:163:26: warning: variable mm_gc set but not used [-Wunused-but-set-variable]

commit 1e714e54 ("powerpc: qe_lib-gpio: use gpiochip data pointer")
left behind this unused variable.
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Chen Zhou <chenzhou10@huawei.com>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Li Yang <leoyang.li@nxp.com>

drivers/soc/fsl/qe/gpio.c

@@ -160,7 +160,6 @@ struct qe_pin *qe_pin_request(struct device_node *np, int index)
 {
 	struct qe_pin *qe_pin;
 	struct gpio_chip *gc;
-	struct of_mm_gpio_chip *mm_gc;
 	struct qe_gpio_chip *qe_gc;
 	int err;
 	unsigned long flags;
@@ -186,7 +185,6 @@ struct qe_pin *qe_pin_request(struct device_node *np, int index)
 		goto err0;
 	}
 
-	mm_gc = to_of_mm_gpio_chip(gc);
 	qe_gc = gpiochip_get_data(gc);
 
 	spin_lock_irqsave(&qe_gc->lock, flags);