audio: pull down audio I2S pins [1/1]

audio: pull down audio I2S pins [1/1]

PD#TV-2362

Problem:
A DC voltage is always there about 300ms.
And coupled with LRCLK and SCLK which
may cause a toggle an DAC side.

Solution:
Pull down the data pin to clear
the DC level.

Verify:
Local verified.

Change-Id: Ib7aff22c44dcec2f653b7ed29495e5e52c16e038
Signed-off-by: Shuai Li <shuai.li@amlogic.com>