pinctrl: at91: drop unneeded dependency on OF_GPIO

This driver does not use any symbols from gpiolib-of.c. There's no
reason for it to select OF_GPIO directly. This addresses a kismet issue
reported by the build bot.

Fixes: 8e86af6 ("pinctrl: at91: allow building the module with COMPILE_TEST=y")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202505010447.kUlI61vt-lkp@intel.com/
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Link: https://lore.kernel.org/20250502100841.113091-1-brgl@bgdev.pl
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Author: Bartosz Golaszewski

drivers/pinctrl/Kconfig

@@ -107,7 +107,6 @@ config PINCTRL_AT91
 	select PINMUX
 	select PINCONF
 	select GPIOLIB
-	select OF_GPIO
 	select GPIOLIB_IRQCHIP
 	help
 	  Say Y here to enable the at91 pinctrl driver