staging:iio: Allow to build SoC specific drivers when COMPILE_TEST is set

None of the SPEAr, LPC32XX or MXS ADC drivers have a compile time dependency on
their respective platform. So make it possible to build the drivers when
CONFIG_COMPILE_TEST is set. This makes it easier to compile test changes.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Reviewed-by: Marek Vasut <marex@denx.de>
Cc: Stefan Roese <sr@denx.de>
Cc: Roland Stigge <stigge@antcom.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

drivers/staging/iio/adc/Kconfig

@@ -102,7 +102,7 @@ config AD7280
 
 config LPC32XX_ADC
 	tristate "NXP LPC32XX ADC"
-	depends on ARCH_LPC32XX
+	depends on ARCH_LPC32XX || COMPILE_TEST
 	help
 	  Say yes here to build support for the integrated ADC inside the
 	  LPC32XX SoC. Note that this feature uses the same hardware as the
@@ -113,7 +113,7 @@ config LPC32XX_ADC
 
 config MXS_LRADC
 	tristate "Freescale i.MX23/i.MX28 LRADC"
-	depends on ARCH_MXS
+	depends on ARCH_MXS || COMPILE_TEST
 	select STMP_DEVICE
 	select IIO_BUFFER
 	select IIO_TRIGGERED_BUFFER
@@ -126,7 +126,7 @@ config MXS_LRADC
 
 config SPEAR_ADC
 	tristate "ST SPEAr ADC"
-	depends on PLAT_SPEAR
+	depends on PLAT_SPEAR || COMPILE_TEST
 	help
 	  Say yes here to build support for the integrated ADC inside the
 	  ST SPEAr SoC. Provides direct access via sysfs.