Commit 7329e211 ("USB: root hubs don't
lie about their number of TTs") requires the various platform EHCI
glue modules to set ->has_tt if the root hub has a Transaction
Translator.

The Orion EHCI root hub does have a Transaction Translator, so set
->has_tt in ehci_orion_setup().  This fixes oopsing on plugging in a
low speed device.
Signed-off-by: Lennert Buytenhek <buytenh@marvell.com>
Acked-by: Nicolas Pitre <nico@marvell.com>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>