bnxt_en: Update firmware interface spec to 1.7.6.2.

Features added include WoL and selftest.

Signed-off-by: Deepak Khungar <deepak.khungar@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>