fomu: dcd_fomu: add next_ev support
fomu: dcd_fomu: add next_ev support

Now that we have the `USB_NEXT_EV` register, take advantage of
it to work around issue #207.

Signed-off-by: Sean Cross <d7e19930cc1f42c2d0781f4d9e6f1fe5891bf9cf@xobs.io>

hathach/tinyusb,hathach/tinyusb,hathach/tinyusb