usb: renesas_usbhs: modify device attach method

Current renesas_usbhs had been assigning udev to each urb.
It was executed even though it was device0.
For this reason, the device0 had to set the new device address
which has still not been assigned. (it will be assigned on next step).
Current renesas_usbhs used fixed address for it.
but it is not good for USB hub support.
This patch modifies this issue.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>