power: qpnp-charger: add support to enable 100% duty cycle

This adds support to specify in devicetree whether the
100 percent duty cycle should be set at probe time.

CRs-Fixed: 478372
Change-Id: I8ffd34be8e596562136ff2258218b48880ad02f9
Signed-off-by: David Keitel <dkeitel@codeaurora.org>