usb: xhci-msm-hsic: Add msm_bus vote for hsic controller driver

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

HSIC performance depends upon apps fabric frequency as HSIC
controller has to support high bi-directional data transfers.
Hence, request for high bus bandwidth as long as HSIC is active.

Change-Id: I31a9834a263e6f8a8bb3a521bca1307e66934c00
Signed-off-by: Hemant Kumar <hemantk@codeaurora.org>