bnx2: Reorganize timeout constants.

Move all related timeout constants to the same location.  BNX2
prefix is also added to make them more consistent.

Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: Matt Carlson <mcarlson@broadcom.com>
Signed-off-by: Benjamin Li <benli@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>