bnx2x: Add missing HSI for big-endian machines

Commit e5d3a51c ("bnx2x: extend DCBx support") was missing HSI
changes for big-endian machine, breaking compilation on such
platforms.

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Yuval Mintz <Yuval.Mintz@qlogic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>