be2net: Implement initiate FW dump feature for Lancer

Added code to initiate FW dump via ethtool. Driver checks if the previous dump
has been cleared before initiating the dump. It doesn't initiate the dump
if it is not cleared.

Signed-off-by: Kalesh AP <kalesh.purayil@emulex.com>
Signed-off-by: Somnath Kotur <somnath.kotur@emulex.com>
Signed-off-by: David S. Miller <davem@davemloft.net>