Revert "liblight: Add battery light support"

This reverts commit 62265ef2b24c3486b2c701d5d3a7d6d1282e6346.

Change-Id: I588b416803b28ad4d18051afde2cdfc66f11c36a
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