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
Signed-off-by: Chet Kener <Cl3Kener@gmail.com>
Enable multicolor lights cm settings

Change-Id: I1cdb5106093e5643895635a9229119bd748da5f0
Signed-off-by: Chet Kener <Cl3Kener@gmail.com>
Overlay: Add ambient mode for hammerhead

Change-Id: I9a879a7741dbaf7a9a4519fb23ad7be702ba9de0