Revert "liblight: Add battery light support"

This reverts commit 217378d3e6a7a5370e7c1583fcfb4ae1e7a9ac7c.
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
Inline kernel