ASoC: WCD9XXX: Add configurable micbias option for headset detection

Micbias is required to perform plug type detection on 3.5mm headset
jack. Some platforms can have the microphone pulled up to micbias using
external on-board pull up resistor or using the pull up resistor
internal to the codec. Add support for headset detection logic to
support configurable option for internal or external micbias.

CRs-fixed: 539445
Change-Id: I9438812f0a924c22932dacc56181cf997625e056
Signed-off-by: Bhalchandra Gajare <gajare@codeaurora.org>