power: qpnp-smbcharger: introduce ICL voting

Currently input current limit (ICL) is tracked and updated in
various locations throughout the driver.

Use the pmic-voter to centralize the ICL for better consistency
and maintainability.

Change-Id: Ic7dfd223c22093fcc2f6c16acff92202f13abf15
Signed-off-by: Nicholas Troast <ntroast@codeaurora.org>