power: qpnp-charger: allow charging in host mode

If host mode is enabled, allow the BATFET to be closed
thus that a DC charger is still able to charge the battery.

Change-Id: I3f863db42b028fa51637d3eb02f0931a02311e27
CRs-Fixed: 495760
Signed-off-by: David Keitel <dkeitel@codeaurora.org>