staging:iio: Move ad799x driver out of staging

The driver is now at a reasonable quality level. Move it out of staging.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Hartmut Knaack <knaack.h@gmx.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index 5553206..a036811 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -96,6 +96,17 @@
 	  To compile this driver as a module, choose M here: the
 	  module will be called ad7923.
 
+config AD799X
+	tristate "Analog Devices AD799x ADC driver"
+	depends on I2C
+	select IIO_BUFFER
+	select IIO_TRIGGERED_BUFFER
+	help
+	  Say yes here to build support for Analog Devices:
+	  ad7991, ad7995, ad7999, ad7992, ad7993, ad7994, ad7997, ad7998
+	  i2c analog to digital converters (ADC). Provides direct access
+	  via sysfs.
+
 config AT91_ADC
 	tristate "Atmel AT91 ADC"
 	depends on ARCH_AT91