bnx2: Fix accidental reversions.

Commit 4ce45e02
"bnx2: Add BNX2 prefix to CHIP ID and name macros"

accidentally reverted 2 commits to use pci_ioumap() and to make
pci_error_handlers const.  This fixes those mistakes.

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