qcacmn: Set the peer ref count to one

For wlan stop modules any pending vdevs flush happens as part
of pdev deinit. If in case of any peer ref count leak, driver
is stuck in dp_pdev_flush_pending_vdevs as the vdev is not getting
cleaned up. This is due to vdev's peer is not deleted. So during
force flush of vdev's peers set the ref count to one before peer
unmap handler.

Change-Id: Ie54996522eac870d00ea7a75c8db40a1cce09d2d
CRs-Fixed: 2658032