iio: adc: Fix dependencies for !HAS_IOMEM archs

Not every arch has io memory.
So, unbreak the build by fixing the dependencies.
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

drivers/iio/adc/Kconfig

@@ -175,6 +175,7 @@ config DA9150_GPADC
 config EXYNOS_ADC
 	tristate "Exynos ADC driver support"
 	depends on ARCH_EXYNOS || ARCH_S3C24XX || ARCH_S3C64XX || (OF && COMPILE_TEST)
+	depends on HAS_IOMEM
 	help
 	  Core support for the ADC block found in the Samsung EXYNOS series
 	  of SoCs for drivers such as the touchscreen and hwmon to use to share
@@ -207,6 +208,7 @@ config INA2XX_ADC
 config IMX7D_ADC
 	tristate "IMX7D ADC driver"
 	depends on ARCH_MXC || COMPILE_TEST
+	depends on HAS_IOMEM
 	help
 	  Say yes here to build support for IMX7D ADC.
 
@@ -409,6 +411,7 @@ config TWL6030_GPADC
 config VF610_ADC
 	tristate "Freescale vf610 ADC driver"
 	depends on OF
+	depends on HAS_IOMEM
 	select IIO_BUFFER
 	select IIO_TRIGGERED_BUFFER
 	help