IPv6: RPL Source Routing Header support

configname: CONFIG_IPV6_RPL_LWTUNNEL

Linux Kernel Configuration
└─>Networking support
└─>Networking options
└─>The IPv6 protocol
└─>IPv6: RPL Source Routing Header support
In linux kernel since version 5.1 (release Date: 2019-05-05)  
Support for RFC6554 RPL Source Routing Header using the lightweight
tunnels mechanism.

If unsure, say N.