power: smb1360: Add SMB1360 Charger and Fuel Gauge driver

SMB1360 is a single path switch-mode battery charger and
fuel gauge. The charger has a max current rating of 1.5A.
The fuel gauge uses battery voltage and coulomb counting
to report the state of charge.

Change-Id: Ic5a0467c1092c068b09428e57b8799c65e3d08d9
Signed-off-by: Anirudh Ghayal <aghayal@codeaurora.org>