ARM: dts: qcom: Add devicetree nodes for smb1396/smb1398 devices

SMB1396 can work as a companion charger in either master or slave role,
and SMB1398 can work as a pre-regulator to regulate the wireless power
from the receiver and provide constant power for downstream chargers,
Add device nodes for them.

Change-Id: I1594c4eab5e477ced6bacd33b754d635d4bdee63