msm: 8064: usb: Allow msm_bus vote when cable is connected

Drivers need to specify their bandwidth requirements to
bus-scaling driver to get guaranteed bandwidth on fabrics.

USB hardware uses a single buffer to transfer data across the
bus. As a result USB performance is highly dependent on system
fabric frequency as USB controller continuously sends NAKs on
the USB BUS unless complete buffer is filled/drained to the memory.
Hence, request for high bus bandwidth as long as USB cable is
connected to improve USB throughput.

Change-Id: I648755f1f7916c2b23e1eecf6cfdb66905792399
Signed-off-by: Hemant Kumar <hemantk@codeaurora.org>