asoc: codecs: wcd938x: check for device up before writes

During SSR, codec device will be down and wait till
receiving up notification before doing any register
reads or writes.

Change-Id: I0e2967990bfc9d0d780d4c7e666a4c31159e70ce
Signed-off-by: Karthikeyan Mani <kmani@codeaurora.org>

asoc/codecs/wcd938x/internal.h

@@ -99,6 +99,7 @@ struct wcd938x_priv {
 	struct snd_info_entry *variant_entry;
 	int flyback_cur_det_disable;
 	int ear_rx_path;
+	bool dev_up;
 };
 
 struct wcd938x_micbias_setting {