power_supply: Add driver for LTC4088 Charger

LTC4088 is high efficiency USB powerpath controller
and Li-Ion/Polymer battery charger. This driver
enables the charger, allows to set current limits,
and detection.

Change-Id: I844431210cfd6e71d02fa7ffb730ee56d8417273
Signed-off-by: Jay Chokshi <jchokshi@codeaurora.org>