usb: gadget: renesas_usbhs: disable pipe on top of interrupt

When data read interrupt happened, the pipe is BUF which means "enable".
then, next un-necessary interrupt/token might be
issued again when all data were popped from fifo.
It will cause un-understandable bug.
This patch decides pipe disable on top of read interrupt.

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