ASoC: codecs: add wm8524 codec driver

WM8524 is a 24-bit 192KHz stereo digital/analog converter (DAC) with
integral charge pump and a simple hardware control interface.
Product information can be found at:
https://www.cirrus.com/products/wm8524/

Signed-off-by: Mihai Serban <mihai.serban@nxp.com>
Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>