usb: dwc3: ep0: fix status phase delayed status direction

commit 68d3e668 (usb: dwc3: ep0: fix for possible early
delayed_status) added handling for early delayed status,
but the current code only works because so far delayed
status will always be on the IN direction.

This patch makes the code more robust by making sure that
we can handle all directions properly.

Signed-off-by: Felipe Balbi <balbi@ti.com>