ASoC: sun4i-i2s: Add 20 and 24 bit support

Extend the functionality of the driver to include support of 20 and
24 bits per sample.

Signed-off-by: Marcus Cooper <codekipper@gmail.com>
Acked-by: Maxime Ripard <mripard@kernel.org>
Reviewed-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Clément Péron <peron.clem@gmail.com>
Link: https://lore.kernel.org/r/20201030144648.397824-7-peron.clem@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>