Add DHCP options and DHCP operation code global definitions
Add DHCP options and DHCP operation code global definitions

Change-Id: Ide19a6e660044bf379cae31856c872b0a8c32600

openstack/dragonflow,openstack/dragonflow,neoareslinux/dragonflow,FrankDuan/df_code,FrankDuan/df_code,neoareslinux/dragonflow,openstack/dragonflow,FrankDuan/df_code