iio: Fix mag3110 Kconfig dependencies

Signed-off-by: Peter Meerwald <pmeerw@pmeerw.net>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
diff --git a/drivers/iio/magnetometer/Kconfig b/drivers/iio/magnetometer/Kconfig
index 0cf0963..d86d226 100644
--- a/drivers/iio/magnetometer/Kconfig
+++ b/drivers/iio/magnetometer/Kconfig
@@ -19,6 +19,8 @@
 config MAG3110
 	tristate "Freescale MAG3110 3-Axis Magnetometer"
 	depends on I2C
+	select IIO_BUFFER
+	select IIO_TRIGGERED_BUFFER
 	help
 	  Say yes here to build support for the Freescale MAG3110 3-Axis
 	  magnetometer.