audio: limit sampling rates to 192Khz for WCD9380 varient.

 -WCD9380 supports sampling rates upto 192Khz, hence limit
  SR > 192Khz to 192Khz.

Change-Id: I1435919320d784bedf4147a9e467867d777b594b
diff --git a/hal/msm8974/platform.h b/hal/msm8974/platform.h
index 1d56a7e..0274b21 100644
--- a/hal/msm8974/platform.h
+++ b/hal/msm8974/platform.h
@@ -372,6 +372,7 @@
 #define DEFAULT_VOLUME_RAMP_DURATION_MS 20
 #define MIXER_PATH_MAX_LENGTH 100
 #define CODEC_VERSION_MAX_LENGTH 100
+#define CODEC_VARIANT_MAX_LENGTH 100
 
 #define MAX_VOL_INDEX 5
 #define MIN_VOL_INDEX 0