USB: EHCI: Add Marvell Host Controller driver

This patch adds support for EHCI compliant HSUSB Host controller found
on Marvell Socs.

It fits both OTG and SPH controller on marvell Socs, including
PXA9xx/MMP2/MMP3/MGx.

Signed-off-by: Neil Zhang <zhangwm@marvell.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>