If Mic Bias is high Z by default and when the LDOH is enabled, the Mic Bias output can pull-up to a non-zero voltage if there is no loading or if the load leakage is very small. Pulling down the Mic Bias output so it is not in high Z to eliminate the floating voltage. Change-Id: I38e76a8c03107879727564f177b2713c9dfa4631 CRs-Fixed: 368898 Signed-off-by: Kuirong Wang <kuirongw@codeaurora.org>