power: smb358-charger: Add smb358 charger driver

This driver supports external smb358 switch mode charger,
can reach up to 2A charging current. This driver instead of
original qpnp-charger, will co-work with PMIC internal BMS
(Battery Monitor System).

Change-Id: I4c520e2812284af0af348beae516eba5f95c49f3
Signed-off-by: Zhenhua Huang <zhenhuah@codeaurora.org>