bnx2x: enlarge minimal alignemnt of data offset

This improves the performance of driver on machine with L1_CACHE_SHIFT of at
most 32 bytes [HW was planned for 64-byte aligned fastpath data].

Signed-off-by: Dmitry Kravkov <Dmitry.Kravkov@qlogic.com>
Signed-off-by: Yuval Mintz <Yuval.Mintz@qlogic.com>
Signed-off-by: Ariel Elior <Ariel.Elior@qlogic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>