ASoC: wcd9xxx: Fix detection issue for headsets with threshold on MIC

Add additional check to see whether micbias is enabled
during DCE measurements and if it is enabled update the
condition so that plug type cannot be wrongly classified
as invalid plug type.

Change-Id: Id758e1bc553e1e6dbc81721f00f9c147b11cf390
Signed-off-by: Phani Kumar Uppalapati <phaniu@codeaurora.org>