power: qpnp-smbcharger: draw more current from PMi in parallel chg

Current the smbcharger is splitting the ICL and charge current fairly
naively. This can cause problems where one charger is FCC limited and
another charger is ICL limited, causing a lot of wasted charge current.

Do a better current distribution to maximize the amount of charge
current going into the battery. By default, raise the ICL ratio of the
primary charger up to 60% to avoid issues with system load prematurely
causing the charger to current limit. Lower the FCC ratio back to 50% to
accommodate this.

Also, make both of these properties configurable through module
parameters and device tree in order to accommodate differences in pcb
and battery limitation.

CRs-Fixed: 930588
Change-Id: I77ec8483232e4297936baaad1e9bb4399474d444
Signed-off-by: Xiaozhe Shi <xiaozhes@codeaurora.org>