USB: dummy-hcd needs the has_tt flag

BugLink: http://bugs.launchpad.net/bugs/823296

commit c5c69f3f0dcf9b569c8f3ad67f3af92cfcedac43 upstream.

Like with other host controllers capable of operating at both high
speed and full speed, we need to indicate that the emulated controller
presented by dummy-hcd has this ability.  Otherwise usbcore will not
accept full-speed gadgets under dummy-hcd.  This patch (as1469) sets
the appropriate has_tt flag.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>