qcom: smb1355: support usbin-usbin parallel configuration

Currently smb1355 only support usbmid-usbmid parallel architecture,
add support for usbin-usbin parallel configuration which allows
ICL split between main and parallel charger.

While at it, add hardware configuration to improve ICL accuracy and
DAC offset/gain.

Change-Id: I71aa05114a735346d45af9d64f42de6da91857e9
Signed-off-by: Ashay Jaiswal <ashayj@codeaurora.org>