ASoC: codecs: add device down ops for swr dmic

When SSR/PDR occurs during record usecase, swr dmic's need
to be shutdown before WCD938x is set to reset low, since swr dmic's
depend on WCD938x for mic bias.
The swr dmic's are shutdown from sound wire master
control during SSR/PDR via driver ops, before WCD938x is shutdown.

Change-Id: I987833b7f44692ff4c91954d65623a17f6b0abdc
Signed-off-by: Vignesh Kulothungan <vigneshk@codeaurora.org>