gpio: omap: Remove set but not used variable 'dev'

Fixes gcc '-Wunused-but-set-variable' warning:

drivers/gpio/gpio-omap.c: In function 'gpio_omap_cpu_notifier':
drivers/gpio/gpio-omap.c:1327:17: warning:
 variable 'dev' set but not used [-Wunused-but-set-variable]
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/gpio/gpio-omap.c

@@ -1306,11 +1306,9 @@ static int gpio_omap_cpu_notifier(struct notifier_block *nb,
 				  unsigned long cmd, void *v)
 {
 	struct gpio_bank *bank;
-	struct device *dev;
 	unsigned long flags;
 
 	bank = container_of(nb, struct gpio_bank, nb);
-	dev = bank->chip.parent;
 
 	raw_spin_lock_irqsave(&bank->lock, flags);
 	switch (cmd) {