ASoC: msm8x10-wcd: Add support for on-demand supplies

There are several supplies needed for audio codec to function. But some
of the supplies can be disabled if not needed to reduce the system power
assumption. Add the support in  the audio codec driver to handle
disable or enable these supplies.

Change-Id: I812f3d63c4612d22dce9c0b1ad7e79f3f227f009
CRs-Fixed: 480759
Signed-off-by: Kuirong Wang <kuirongw@codeaurora.org>