ASoC: sun4i-i2s: Add support for A83T

The I2S controller in the A83T is mostly compatible with the one found
in earlier SoCs such as the A20 and A31. While the documents publicly
available for the A83T do not cover this hardware, the officially
released BSP kernel does have register definitions for it. These were
matched against the A20 user manual. The only difference is the TX FIFO
and interrupt status registers have been swapped around, like what we
have seen with the SPDIF controller.

This patch adds support for this hardware.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Mark Brown <broonie@kernel.org>