netxen: fix ethtool register dump

o Dump registers such as tx ring and rx ring counter, firmware state,
  niu regs, etc. which can be useful for debugging purpose.

Signed-off-by: Sucheta Chakraborty <sucheta.chakraborty@qlogic.com>
Signed-off-by: Amit Kumar Salecha <amit.salecha@qlogic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>