Loading firmware when actually bringing eth device up.
This also will allow driver to be insmoded when filesystem with
firmware files is not available yet.

Suggested by Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: NDmitry Kravkov <dmitry@broadcom.com>
Signed-off-by: NEilon Greenstein <eilong@broadcom.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>