extcon: arizona: Use bypass mode for MICVDD

We can perform microphone detection with MICVDD in bypass mode so try to
enable that during startup for minimal power - other users or machine
constraints will prevent bypass mode being activated if it is unsuitable.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>