bnx2x: Add support for single-port DCBx

Driver is currently looking at shared information for determining whether
DCBx can be supported for a given port.
On 4-port devices, up-to-date management firmware can support DCBx on
each port of a given engine independently - but that would cause bnx2x to
misinterpert the support and assume DCBx is supported on both.

Signed-off-by: Yuval Mintz <Yuval.Mintz@qlogic.com>
Signed-off-by: Ariel Elior <Ariel.Elior@qlogic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c

@@ -12429,8 +12429,10 @@ static int bnx2x_init_bp(struct bnx2x *bp)
 
 	if (SHMEM2_HAS(bp, dcbx_lldp_params_offset) &&
 	    SHMEM2_HAS(bp, dcbx_lldp_dcbx_stat_offset) &&
+	    SHMEM2_HAS(bp, dcbx_en) &&
 	    SHMEM2_RD(bp, dcbx_lldp_params_offset) &&
-	    SHMEM2_RD(bp, dcbx_lldp_dcbx_stat_offset)) {
+	    SHMEM2_RD(bp, dcbx_lldp_dcbx_stat_offset) &&
+	    SHMEM2_RD(bp, dcbx_en[BP_PORT(bp)])) {
 		bnx2x_dcbx_set_state(bp, true, BNX2X_DCBX_ENABLED_ON_NEG_ON);
 		bnx2x_dcbx_init_params(bp);
 	} else {