ASoC: wcd9306: Setting DMIC clk lines to low

DMIC clock lines are high even after recording
is stopped. DMIC clk lines are holding the last
value. Manually forcing the digital mic clock
lines to low.

CRs-Fixed: 1067974
Change-Id: I760416da7ced36bc0a7dfbaca026b2a5e56d0d0c
Signed-off-by: Surendar karka <sukark@codeaurora.org>