uboot-imx

dm: usb: Do not scan companion buses if no devices where handed over

USB scanning is slow, and there is no need to scan the companion buses
if no usb devices where handed over to the companinon controllers by any
of the main controllers.

This saves e.g. 2 seconds when booting a A10 OLinuxIno Lime with no USB-1
devices plugged into the root usb ports.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Simon Glass <sjg@chromium.org>