wb_port_arbiter: fix cache coherency during wb block write

Multiples write can occur during a single write block cycle.

Old code triggers a buffer write on the rising edge of wb_cyc.
This only works with single write cycles.

This patch signals that a write have happend to all ports
on every wb_ack during the write block cycle.

Signed-off-by: Franck Jullien <franck.jullien@gmail.com>
systems: add Altera NEEK board

This patch adds supports for the Altera NEEK board.

The systems supports:
- UART,
- Ethernet,
- VGA/LCD controller,
- SD-CARD (SPI mode),
- NOR flash.

Signed-off-by: Franck Jullien <franck.jullien@gmail.com>
neek: connect ibus to cfi0
neek: add cfi to the test bench
Make ROM optional