gpio: GPIO_MVEBU should not default to y when compile-testing

Merely enabling compile-testing should not enable additional
functionality.

Fixes: 956ee0c ("gpio: mvebu: allow building the module with COMPILE_TEST=y")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/6b9e55dbf544297d5acf743f6fa473791ab10644.1733242798.git.geert+renesas@glider.be
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

drivers/gpio/Kconfig

@@ -482,8 +482,9 @@ config GPIO_MT7621
 	  Say yes here to support the Mediatek MT7621 SoC GPIO device.
 
 config GPIO_MVEBU
-	def_bool y
+	bool "Marvell Orion and EBU GPIO support" if COMPILE_TEST
 	depends on PLAT_ORION || ARCH_MVEBU || COMPILE_TEST
+	default PLAT_ORION || ARCH_MVEBU
 	select GENERIC_IRQ_CHIP
 	select REGMAP_MMIO