pinctrl: lantiq: Release gpiochip resources in fail case

This patch releases gpiochip resources with of_gpiochip_remove
and gpiochip_remove in failure cases.

CC: John Crispin <blogic@openwrt.org>
CC: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Pramod Gurav <pramod.gurav@smartplayin.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>