mfd: Allow compile test of GPIO consumers if !GPIOLIB

The GPIO subsystem provides dummy GPIO consumer functions if GPIOLIB is
not enabled. Hence drivers that depend on GPIOLIB, but use GPIO consumer
functionality only, can still be compiled if GPIOLIB is not enabled.

Relax the dependency on GPIOLIB if COMPILE_TEST is enabled, where
appropriate.

Signed-off-by: Geert Uytterhoeven <[e-mail]>
Signed-off-by: Lee Jones <[e-mail]>

drivers/mfd/Kconfig

···
 config MFD_AAT2870_CORE
 	bool "AnalogicTech AAT2870"
 	select MFD_CORE
-	depends on I2C=y && GPIOLIB
+	depends on I2C=y
+	depends on GPIOLIB || COMPILE_TEST
 	help
 	  If you say yes here you get support for the AAT2870.
 	  This driver provides common support for accessing the device,
···
 
 config MFD_TPS65910
 	bool "TI TPS65910 Power Management chip"
-	depends on I2C=y && GPIOLIB
+	depends on I2C=y
+	depends on GPIOLIB || COMPILE_TEST
 	select MFD_CORE
 	select REGMAP_I2C
 	select REGMAP_IRQ