asoc: codecs: Add variant entry support for wcd937x and wcd938x

Add variant entry support for wcd937x and wcd938x codecs to
differentiate between wcd9370/80 and wcd9375/85 variants.

Change-Id: Ife20d14462a0b0968e0458471af3823872592e10
Signed-off-by: Aditya Bavanari <abavanar@codeaurora.org>

asoc/codecs/wcd938x/internal.h

@@ -94,6 +94,7 @@ struct wcd938x_priv {
 	/* Entry for version info */
 	struct snd_info_entry *entry;
 	struct snd_info_entry *version_entry;
+	struct snd_info_entry *variant_entry;
 	int flyback_cur_det_disable;
 	int ear_rx_path;
 };