netxen: annotate board_config and board_type

Remove huge board config structure from each instance, read
only necessary fields from flash.

Replace board_type with port_type (1G/10G), there's another
board_type field describing card type (SFP/XFP/CX4).

Signed-off-by: Dhananjay Phadke <dhananjay@netxen.com>
Signed-off-by: David S. Miller <davem@davemloft.net>