ASoC: codecs: wcd938x: make sdw dependency explicit in Kconfig

currenlty wcd938x has only soundwire interface and depends on
symbols from wcd938x soundwire module, so make this dependency
explicit in Kconfig

Without this one of the randconfig endup setting
CONFIG_SND_SOC_WCD938X=y
CONFIG_SND_SOC_WCD938X_SDW=m
resulting in some undefined reference to wcd938x_sdw* symbols.

Reported-by: kernel test robot <lkp@intel.com>
Fixes: 0454422288 ("ASoC: codecs: wcd938x: add audio routing and Kconfig")
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20210713140417.23693-1-srinivas.kandagatla@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/codecs/Kconfig

@@ -1557,6 +1557,7 @@ config SND_SOC_WCD934X
 	  Qualcomm SoCs like SDM845.
 
 config SND_SOC_WCD938X
+	depends on SND_SOC_WCD938X_SDW
 	tristate
 
 config SND_SOC_WCD938X_SDW