ASoC: cs47l15: Add codec driver for Cirrus Logic CS47L15

Adds the codec driver for the CS47L15 SmartCodec. This is a
multi-functional codec based on the Cirrus Logic Madera platform.

Signed-off-by: Richard Fitzgerald <rf@opensource.wolfsonmicro.com>
Signed-off-by: Jaswinder Jassal <jjassal@opensource.wolfsonmicro.com>
Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20190725163931.24964-2-ckeepax@opensource.cirrus.com


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