audio: fix no sound when atv switch to other source [1/1]

PD#SWPL-3440

Problem:
ATV switch to other source, such as DTV/HDMI/AV, no sound

Solution:
ATV switch to other source, atv demond is disabled when
audio is reading data, so it's blocked.
In normal, ATV sends audio data to FRATV,
then FRATV sends data to audio fifo, then to DDR.
If ATV stops to send audio data, no interrupt from FRATV to fifo,
no data is updated to DDR.
When exit from audio atv patch, it's a block signal to
wait in_read finished, but ATV is disabled
TimeCheckThread will check any routine is blocked,
if there is one, signal SIGABRT would rise and cause audio server restart
So we  make a delay before ATV is disabled to waiting audio data is readed.

Verify:
x301

Change-Id: I47dc88d2c8565c16c739ffea69a88152fa4d5f13
Signed-off-by: Xing Wang <xing.wang@amlogic.com>

drivers/amlogic/atv_demod/atv_demod_ops.c

@@ -175,6 +175,8 @@ int atv_demod_leave_mode(struct dvb_frontend *fe)
 	priv->state = ATVDEMOD_STATE_IDEL;
 	priv->standby = true;
 
+	usleep_range(30 * 1000, 30 * 1000 + 100);
+
 	if (priv->afc.disable)
 		priv->afc.disable(&priv->afc);