USB: add ehci-ixp bus glue

EHCI Glue driver for Intel IXP4XX EHCI USB controller

Signed-off-by: Vladimir Barinov <vbarinov@ru.mvista.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>