pinctrl: remove pinctrl_remove_gpio_range

The gpio ranges will be automatically removed when the pinctrl
driver is unregistered.

Acked-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Dong Aisheng <dong.aisheng@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>