ASoC: update headers for upstream compliance

Update uapi header reference path to include
path prefix "audio/"

Change-Id: Ic7b1d22910b07be3ffe8d9f02514ed89facea974
Signed-off-by: Vignesh Kulothungan <vigneshk@codeaurora.org>

asoc/codecs/wcd934x/wcd934x.c

@@ -20,7 +20,7 @@
 #include <linux/regmap.h>
 #include <linux/spi/spi.h>
 #include <linux/regulator/consumer.h>
-#include <linux/mfd/wcd9xxx/wcd9xxx_registers.h>
+#include <audio/linux/mfd/wcd9xxx/wcd9xxx_registers.h>
 #include <soc/swr-wcd.h>
 #include <soc/snd_event.h>
 #include <sound/pcm.h>