gpio: Remove the unused flags

gpio: Remove the unused flags

drivers/gpio/gpio-grgpio.c: In function ‘grgpio_remove’:
drivers/gpio/gpio-grgpio.c:438:16: warning: unused variable ‘flags’ [-Wunused-variable]
  unsigned long flags;
                 ^
Fixes: 0bf3867a99bd ("gpio: gpio-grgpio: fix possible sleep-in-atomic-context bugs in grgpio_remove()")
Signed-off-by: Shaokun Zhang <zhangshaokun@hisilicon.com>
Link: https://lore.kernel.org/r/1579009062-7154-1-git-send-email-zhangshaokun@hisilicon.com
Reviewed-by: Bartosz Golaszewski <bgolaszewski@baylibre.com
Reviewed-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>