[PATCH] netconsole support for b44

This patch adds poll support to the b44 driver to allow netconsole 
support. Style lifted straight from 8139too.c

here is the dmesg output with it in place:

netconsole: device eth0 not up yet, forcing it
netconsole: carrier detect appears flaky, waiting 10 seconds
b44: eth0: Link is down.
b44: eth0: Link is up at 100 Mbps, full duplex.
b44: eth0: Flow control is on for TX and on for RX.
netconsole: network logging started

output confirmed by netcat on other system.

Signed-off-by: Con Kolivas <redacted>