ASoC: sun4i-i2s: Fix the LRCK polarity

The LRCK polarity "normal" polarity in the I2S/TDM specs and in the
Allwinner datasheet are not the same. In the case where the i2s controller
is being used as the LRCK master, it's pretty clear when looked at under a
scope.

Let's fix this, and add a comment to clear up as much the confusion as
possible.

Fixes: 7d299381 ("ASoC: sun4i-i2s: Add support for H3")
Fixes: 21faaea1 ("ASoC: sun4i-i2s: Add support for A83T")
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
Link: https://lore.kernel.org/r/e03fb6b2a916223070b9f18405b0ef117a452ff4.1566242458.git-series.maxime.ripard@bootlin.com


Signed-off-by: Mark Brown <broonie@kernel.org>