cxgb4 : Handle dcb enable correctly

commit 3bb06261 upstream.

Disabling DCBx in firmware automatically enables DCBx for control via host
lldp agents. Wait for an explicit setstate call from an lldp agents to enable
 DCBx instead.

Fixes: 76bcb31e ("cxgb4 : Add DCBx support codebase and dcbnl_ops")

Signed-off-by: Anish Bhatt <anish@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>