ASoC: sun4i-spdif: Move quirks to the top

The quirks are actually defines in the middle of the file with
short explanation.

Move this at the top and add a section to have coherency with
sun4i-i2s.

Signed-off-by: Clément Péron <peron.clem@gmail.com>
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
Signed-off-by: Mark Brown <broonie@kernel.org>