mainboard/google/reef: turn off DMIC_CLK_B1 in S0ix

Wake On Voice stream capture configuration is mono. It is sufficient
to keep DMIC_CLK_A1 on in S0ix; so, turning off DMIC_CLK_B1.
Power saving should be visible in the boards which has more
than one DMIC connected.

BUG=None
BRANCH=None
TEST=WoV and quad channel DMIC capture works

Change-Id: Ic46d4c7b30b945eba47a05d78386f48e4a675a03
Signed-off-by: Sathyanarayana Nujella <sathyanarayana.nujella@intel.com>
Reviewed-on: https://review.coreboot.org/19018
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-by: Venkateswarlu V Vinjamuri <venkateswarlu.v.vinjamuri@intel.com>
Tested-by: build bot (Jenkins)
1 file changed