ASoC: wcd9335: Add support for enabling standalone micbias

Currently micbias enablement is tied to audio recording
use-cases. However, there are few audio use-cases where
just only micbias needs to be enabled. Add support for
enabling standalone micbias.

Change-Id: Iaad27895a9f1811f97b39ea08ca9d0d80758a6f8
Signed-off-by: Phani Kumar Uppalapati <phaniu@codeaurora.org>