be2net: do not use sli_family to identify skyhawk-R chip

SKYHAWK_FAMILY will not identify all revisions of the chip.
Use device-id check (skyhawk_chip() macro) instead.

Signed-off-by: Sathya Perla <sathya.perla@emulex.com>
Signed-off-by: David S. Miller <davem@davemloft.net>