in order to guarantee i2s lrck signal integrity, when i2s stop,
need at least one lrck cycle to ensure signal integrity.

the max delay time is when lrck is 8khz, the delay time is
125us(1/8khz), using udelay(150) with a 25us margin.
Signed-off-by: Sugar Zhang <sugar.zhang@rock-chips.com>
Signed-off-by: Mark Brown <broonie@kernel.org>