bnx2x: fix receive of VF->PF mailbox messages by the PF on big-endian

On ppc64 the PF did not receive messages from VFs correctly.

Fields of struct vf_pf_event_data are little-endian.

Signed-off-by: Michal Schmidt <mschmidt@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>