ASoC: wcd9xxx: Fix issue for headset when detected as lineout

Fix issue when headset is detected as lineout with slow insertion.
Headset is detected as lineout when initial DCE measurements show
voltages near microphone bias detecting as HIGH_HPH and even MIC
schmitt trigger does not trigger the headset insertion interrupt
when fully inserted. To avoid false detection, measure DCE voltages
continuously by enabling polling and then report the plug type.
At the end of polling, if it still reports lineout, enable MIC
schmitt trigger for further detection.

Change-Id: I0a5cb5f3a82a69a6e3ad4a31d5b4f31c5889b6fa
CRs-fixed: 470446
Signed-off-by: Phani Kumar Uppalapati <phaniu@codeaurora.org>