ASoC: alc5632: Added support of two undocumented registers

There are two undocumented registers in use in alc5632_i2c_probe
function. It must be added to support future rewrite of this
function to use regmap API completely.

Signed-off-by: Leon Romanovsky <leon@leon.nu>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>