ASoC: sun4i-spdif: Add quirks to the spdif driver

It has been seen that some newer SoCs have a different TX FIFO
address and we already have the difference with the A31 requiring
a reset. Add a quirks structure so that these can be managed
easily.

Signed-off-by: Marcus Cooper <codekipper@gmail.com>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Mark Brown <broonie@kernel.org>