[U-Boot] EHCI-OMAP driver and DM compatibility

[Adam Ford]

I know there are a bunch of boards with omap EHCI host support and
with the pending DM_USB requirement, I was curious to see if anyone
has started this.  I've got two boards that are impacted by this, and
I was going to look at migrating the driver, but I don't want to
duplicate efforts if some have been started.  If somone has started,
I'd love to either help and/or test the driver.

adam