ASoC: codecs: Put the CODEC drivers in a menu

Now they're visible they get a bit noisy.
Signed-off-by: Mark Brown <broonie@linaro.org>

sound/soc/codecs/Kconfig

@@ -8,6 +8,8 @@ config SND_SOC_I2C_AND_SPI
 	default y if I2C=y
 	default y if SPI_MASTER=y
 
+menu "CODEC drivers"
+
 config SND_SOC_ALL_CODECS
 	tristate "Build all ASoC CODEC drivers"
 	depends on COMPILE_TEST
@@ -584,3 +586,5 @@ config SND_SOC_ML26124
 config SND_SOC_TPA6130A2
 	tristate "Texas Instruments TPA6130A2 headphone amplifier"
 	depends on I2C
+
+endmenu