[TG3]: Add management FW version to ethtool report

This patch appends the management firmware version to the bootcode
firmware string reported through ethtool.

Signed-off-by: Matt Carlson <mcarlson@broadcom.com>
Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>