Revert "hammerhead: Enable ZSL mode for camera"

Seems to be a problem with the latest kernel updates

This reverts commit 1037a455f9a6a090545801c2e25cd195dd69cc96.
Revert "liblight: Add battery light support"

This reverts commit 2b8636625a5fec47bb6b9a65f490b6d3864025cb.
hammerhead: add charging led support

Also introduces led priority handling for
battery vs notification vs attention
(copied from jf-common).

Requires the hammerhead kernel led
always on support patch.

Change-Id: I1a2f3aae457c6d7e4e3c3f9ca39cbe42d39c3bc2