USB: ohci: introduce omap3 ohci-hcd driver

Add support for the OHCI controller present in OMAP3 and newer chips.

The code is mostly based off the ehci-omap.c driver.
Some of it is common to both drivers and will eventually
need to be factored out to platform init files.

In its current state, the driver cannot co-exist with the ehci-omap
driver, and this will be fixed in later versions. The second driver
to be loaded will overwrite settings made by the other. For now,
this driver should allow the few users of OMAP3 OHCI to get going.
Signed-off-by: Anand Gadiyar <gadiyar@ti.com>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>