ASoC: sunxi: sun50i-codec-analog: Add earpiece

This adds the necessary registers and audio routes to play audio using
the Earpiece, that's supported on the A64.

Signed-off-by: Luca Weiss <luca@z3ntu.xyz>
Reviewed-by: Chen-Yu Tsai <wens@csie.org>
Link: https://lore.kernel.org/r/20190703184814.27191-1-luca@z3ntu.xyz


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