power: qpnp-smbcharger: update USB handling at boot-up

During boot-up USB handling in charger driver is done
twice causing multiple notifications to USB driver. Fix this
by removing call to src_detect_handler and handling USB state
in handle_usb_insertion/removal.

CRs-Fixed: 1035576
Change-Id: I439984815a2ad6a32bfb733ee83c2c4828786d06
Signed-off-by: Ashay Jaiswal <ashayj@codeaurora.org>