ASoC: codecs: sdm660_cdc: Fix pop noise issue at DMIC

Pop noise occurs during switch from handset to speaker mode
during voice call. This is because sufficient delay
is not provided for tx to unmute. A delayed workqueue
that will do unmute at the end solves the issue.

CRs-Fixed: 2101423
Change-Id: I1ae7068b23158bb8428d5b96e9f65fb05a67ff7e
Signed-off-by: Vatsal Bucha <vbucha@codeaurora.org>