ASoC: Add PCM1792A spi mode codec support

Add PCM1792A spi mode codec support. This version implements only
a subset of functionalities. Tested connect to a pandaboard ES
device and based on recently pcm1681 codec.

Signed-off-by: Michael Trimarchi <michael@amarulasolutions.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
diff --git a/sound/soc/codecs/Kconfig b/sound/soc/codecs/Kconfig
index badb6fb..4afe943 100644
--- a/sound/soc/codecs/Kconfig
+++ b/sound/soc/codecs/Kconfig
@@ -54,6 +54,7 @@
 	select SND_SOC_MC13783 if MFD_MC13XXX
 	select SND_SOC_ML26124 if I2C
 	select SND_SOC_HDMI_CODEC
+	select SND_SOC_PCM1792A if SPI_MASTER
 	select SND_SOC_PCM3008
 	select SND_SOC_RT5631 if I2C
 	select SND_SOC_RT5640 if I2C
@@ -292,6 +293,9 @@
 config SND_SOC_HDMI_CODEC
        tristate
 
+config SND_SOC_PCM1792A
+       tristate
+
 config SND_SOC_PCM3008
        tristate