ASoC: wm8974: add devicetree support

This adds devicetree support to the wm8974 codec driver.
With a DT-based kernel, there is no board-specific setting
to select the driver so allow it to be manually chosen.

Signed-off-by: Mans Rullgard <mans@mansr.com>
Acked-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
diff --git a/sound/soc/codecs/Kconfig b/sound/soc/codecs/Kconfig
index cfdafc4..e36b14c 100644
--- a/sound/soc/codecs/Kconfig
+++ b/sound/soc/codecs/Kconfig
@@ -838,7 +838,8 @@
 	tristate
 
 config SND_SOC_WM8974
-	tristate
+	tristate "Wolfson Microelectronics WM8974 codec"
+	depends on I2C
 
 config SND_SOC_WM8978
 	tristate "Wolfson Microelectronics WM8978 codec"