power: qpnp-charger: do not set trim to 0 on USB DCP removal

Currently the charger driver sets IUSB_TRIM to 0 upon USB DCP
insertion. This can lead to unintended reverse boost and removal
detection issues.

Fix this by restoring the trim default instead upon USB removal
instead.

CRs-Fixed: 688143
Change-Id: Ic9d8bd8f8b016044c06c30b878405346755469ae
Signed-off-by: David Keitel <dkeitel@codeaurora.org>