If the receiver runs out of space for an received frame in the internal
FIFO or the in-RAM descriptors it will switch to RX_IDLE from where it
is not restarted.
We used to deal with RX_IDLE by doing a total reinit but this lost
our link and caused a potential 30sec autonegotiation against
switches. This was changed to a less heavyhanded approach, but this
failed to restart the receiver it it were in the RX_IDLE state.
This change adds the RX_IDLE and the RX_FIFO_OFLOW conditions as
triggers for interrupts and receive side processing, and restarts
the receiver when it is RX_IDLE.
Remove the #ifdef notyet'ed nge_rxeoc() function.
Sponsored by: Cybercity Internet, Denmark.
MFC after: 7 days