usb: ehci: add Host Bus Manager (HBM) support

HBM is a new HW unit which transfers USB bulk data packets in
BAM to BAM mode between the USB BAM and a peer BAM in USB
host mode.

This ability reduces the SW interfere in host mode for data
packets transmission. This is done by the HBM HW which generates
"infinite" USB (bulk) transfers against the USB core.

This change adds the HBM SW driver.

Change-Id: I63febd699b1edca71a56a2d7d2b41f25d5e48447
Signed-off-by: Shimrit Malichi <smalichi@codeaurora.org>