ASoC: wm8991: Use a supply to manage input power

Instead of using a fake register and events to manage input power use a
supply to do the job, saving code and preparing for regmap conversion of
the driver.

Signed-off-by: Mark Brown <broonie@linaro.org>
Acked-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
2 files changed