pinctrl: lantiq: Remove unused of_gpio.h inclusion

The of_gpio.h is not and shouldn't be used in the drivers. Remove it.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20230615164204.25462-1-andriy.shevchenko@linux.intel.com


Signed-off-by: Linus Walleij <linus.walleij@linaro.org>