bnxt: initialize board_info values with proper enums

initialize board_info values with proper enums for defensive programming
purposes.  This will avoid any errors of the enums being declared not
lining up with the board_info array.

Signed-off-by: Scott Branden <scott.branden@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>