usb: renesas_usbhs: fixup dma transfer stall

renesas_usbhs driver can switch DMA/PIO transfer by using handler,
and each handler have push/pop direction.
But unfortunately, current dma push handler didn't a path
which calls usbhs_pipe_enable(). Thus, dma transfer never happened.
this patch fixes it.

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