Merge branch 'seg6.end.dt6'

Andrea Mayer says:

====================
seg6: add support for SRv6 End.DT46 Behavior

SRv6 End.DT46 Behavior is defined in the IETF RFC 8986 [1] along with SRv6
End.DT4 and End.DT6 Behaviors.

The proposed End.DT46 implementation is meant to support the decapsulation
of both IPv4 and IPv6 traffic coming from a *single* SRv6 tunnel.
The SRv6 End.DT46 Behavior greatly simplifies the setup and operations of
SRv6 VPNs in the Linux kernel.

 - patch 1/2 is the core patch that adds support for the SRv6 End.DT46
   Behavior;

 - patch 2/2 adds the selftest for SRv6 End.DT46 Behavior.

The patch introducing the new SRv6 End.DT46 Behavior in iproute2 will
follow shortly.

Comments, suggestions and improvements are very welcome as always!
====================

Signed-off-by: David S. Miller <davem@davemloft.net>