Drivers are not allowed to call printf().  Converted eprintf() to DBG(),
and removed spurious startup banner.

Fixed hardcoded inclusion of little_bswap.h

Use EIO rather than 1 as an error number.

Add ability for network devices to flag link up/down state to the
networking core.

Autobooting code will now wait for link-up before attempting DHCP.

IPoIB reflects the Infiniband link state as the network device link state
(which is not strictly correct; we also need a succesful IPoIB IPv4
broadcast group join), but is probably more informative.

Signed-off-by: Alexey Zaytsev <alexey.zaytsev@gmail.com>

Stripped out trailing whitespace to keep git happy.