ARM: 6177/1: nomadik-gpio: fix "ignoring return value" warning

arch/arm/plat-nomadik/gpio.c: In function 'nmk_gpio_remove':
arch/arm/plat-nomadik/gpio.c:630: warning: ignoring return value of 'gpiochip_remove', declared with attribute warn_unused_result

Because this function is marked __exit and this code can't be built as a
module, this function is never used.  So just remove it, fixing the
warning in the process.

Acked-by: Alessandro Rubini <rubini@unipv.it>
Acked-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Rabin Vincent <rabin.vincent@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>