bnx2x: define event data reserved fields as little-endian

For consistency with other event data structs and to lessen
the chance of a mistake should one of the reserved fields become
used in the future, define the reserved fields as little-endian.

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