iio: adc: exynos_adc: Add support for s3c24xx ADC

This patch add support for s3c2410/s3c2416/s3c2440/s3c2443 ADC. The s3c24xx
is alomost same as ADCv1. But, There are a little difference as following:
- ADCMUX register address
- ADCDAT mask (10 bit or 12 bit ADC resolution according to SoC version)
- s3c24xx/s3c64xx has not included ADC_PHY enable register

Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index 6655fd4..88bdc8f 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -129,7 +129,7 @@
 
 config EXYNOS_ADC
 	tristate "Exynos ADC driver support"
-	depends on ARCH_EXYNOS || (OF && COMPILE_TEST)
+	depends on ARCH_EXYNOS || ARCH_S3C24XX || ARCH_S3C64XX || (OF && COMPILE_TEST)
 	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