gpio: omap: allow building the module with COMPILE_TEST=y

For better build coverage, allow building the gpio-omap driver with
COMPILE_TEST Kconfig option enabled.

While at it: simplify the dependencies and drop the dependency on ARM as
it's already implied by ARCH_OMAP.

Reviewed-by: Alexander Sverdlin <alexander.sverdlin@gmail.com>
Link: https://lore.kernel.org/r/20241205120610.40644-1-brgl@bgdev.pl
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

Author: Bartosz Golaszewski

drivers/gpio/Kconfig

@@ -528,9 +528,9 @@ config GPIO_OCTEON
 	  family of SOCs.
 
 config GPIO_OMAP
-	tristate "TI OMAP GPIO support" if ARCH_OMAP2PLUS || COMPILE_TEST
+	tristate "TI OMAP GPIO support"
+	depends on ARCH_OMAP || COMPILE_TEST
 	default y if ARCH_OMAP
-	depends on ARM
 	select GENERIC_IRQ_CHIP
 	select GPIOLIB_IRQCHIP
 	help