ASoC: rcar: remove un-needed select from Kconfig

config RCAR_CLK_ADG is not exist
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

sound/soc/sh/Kconfig

@@ -37,7 +37,6 @@ config SND_SOC_SH4_SIU
 config SND_SOC_RCAR
 	tristate "R-Car series SRU/SCU/SSIU/SSI support"
 	select SND_SIMPLE_CARD
-	select RCAR_CLK_ADG
 	help
 	  This option enables R-Car SUR/SCU/SSIU/SSI sound support