gpio: mxs: add COMPILE_TEST support for GPIO_MXS

Add COMPILE_TEST support to GPIO_MXS driver for better compile
testing coverage.
Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

drivers/gpio/Kconfig

@@ -400,7 +400,7 @@ config GPIO_MXC
 
 config GPIO_MXS
 	def_bool y
-	depends on ARCH_MXS
+	depends on ARCH_MXS || COMPILE_TEST
 	select GPIO_GENERIC
 	select GENERIC_IRQ_CHIP