ASoC: rockchip-i2s: fix rockchip i2s defination more reasonable

Fix SND_ROCKCHIP_I2S to be more reasonable - SND_SOC_ROCKCHIP_I2S,
SND_SOC_ROCKCHIP_I2S should select by audio driver, instead of
SND_SOC_ROCKCHIP.
Signed-off-by: Jianqun Xu <jay.xu@rock-chips.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/rockchip/Kconfig

@@ -2,11 +2,10 @@ config SND_SOC_ROCKCHIP
 	tristate "ASoC support for Rockchip"
 	depends on COMPILE_TEST || ARCH_ROCKCHIP
 	select SND_SOC_GENERIC_DMAENGINE_PCM
-	select SND_ROCKCHIP_I2S
 	help
 	  Say Y or M if you want to add support for codecs attached to
 	  the Rockchip SoCs' Audio interfaces. You will also need to
 	  select the audio interfaces to support below.
 
-config SND_ROCKCHIP_I2S
+config SND_SOC_ROCKCHIP_I2S
 	tristate

sound/soc/rockchip/Makefile

 # ROCKCHIP Platform Support
 snd-soc-i2s-objs := rockchip_i2s.o
 
-obj-$(CONFIG_SND_ROCKCHIP_I2S) += snd-soc-i2s.o
+obj-$(CONFIG_SND_SOC_ROCKCHIP_I2S) += snd-soc-i2s.o