Add i2c shutdown function to prevent the pop sound of the headphone while
the system is rebooting or shutdowning. It de-initials the jack detection
function, and it cannot be turned off in _BIAS_OFF. If we don't de-initial
it, the pop sound will be heard in the situation of powering off. And
replace the related register settings from magic number to meaningful
defined name.
Signed-off-by: Oder Chiou <oder_chiou@realtek.com>
Signed-off-by: Mark Brown <broonie@kernel.org>