mfd: asic3: Build if COMPILE_TEST=y

Build this driver on another platforms if COMPILE_TEST=y. Another
drivers may depend on this, for example leds-asic3.
Signed-off-by: Marek Behún <marek.behun@nic.cz>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

drivers/mfd/Kconfig

@@ -290,7 +290,8 @@ config MFD_CS47L92
 
 config MFD_ASIC3
 	bool "Compaq ASIC3"
-	depends on GPIOLIB && ARM
+	depends on GPIOLIB
+	depends on ARM || COMPILE_TEST
 	select MFD_CORE
 	help
 	  This driver supports the ASIC3 multifunction chip found on many