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 <[e-mail]>
Acked-by: Tony Lindgren <[e-mail]>
Signed-off-by: Linus Walleij <[e-mail]>

drivers/gpio/gpio-omap.c

···
 				  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) {