power: qpnp-charger: add OCP support for SMBBP/SMBCL

Add over current protection support for the USB
peripheral of SMBBP and SMBCL devices.

The OCP interrupt is used to notify and clear
of over current conditions when reverse boosting for
USB OTG. In an over current condition the hardware
opens the OTG FET but leaves the boost on. The
interrupt handler clears the OCP LATCH and turns
back on the OTG switch.

Change-Id: I329887a6dcde2d9f96aca4fab310783327e024d9
Signed-off-by: David Keitel <dkeitel@codeaurora.org>