gpio: tb10x: fix OF_GPIO dependency

Selecting OF_GPIO is generally not allowed, it always gets enabled
when both GPIOLIB and OF are turned on.

The tb10x driver now warns about this after it was enabled for
compile-testing:

WARNING: unmet direct dependencies detected for OF_GPIO
  Depends on [n]: GPIOLIB [=y] && OF [=n] && HAS_IOMEM [=y]
  Selected by [y]:
  - GPIO_TB10X [=y] && GPIOLIB [=y] && HAS_IOMEM [=y] && (ARC_PLAT_TB10X || COMPILE_TEST [=y])

OF_GPIO is not required for compile-testing and is already enabled
when the driver is usable, so just drop the 'select' line.

Fixes: 682fbb1 ("gpio: tb10x: allow building the module with COMPILE_TEST=y")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20251205095429.1291866-1-arnd@kernel.org
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>

Author: arndb

drivers/gpio/Kconfig

@@ -737,7 +737,6 @@ config GPIO_TB10X
 	depends on ARC_PLAT_TB10X || COMPILE_TEST
 	select GPIO_GENERIC
 	select GENERIC_IRQ_CHIP
-	select OF_GPIO
 
 config GPIO_TEGRA
 	tristate "NVIDIA Tegra GPIO support"