ipv6: gre: setup default multicast routes over PtP links
ipv6: gre: setup default multicast routes over PtP links

GRE point-to-point interfaces should also support ipv6 multicast. Setting
up default multicast routes on interface creation was forgotten. Add it.

Bugzilla: <https://bugzilla.kernel.org/show_bug.cgi?id=103231>
Cc: Julien Muchembled <112f489f6b265cdf4e4892f7b952cd36fc0ecd5f@jmuchemb.eu>
Cc: Eric Dumazet <312c7d941f03386814be517ffdb3e0eb6624e275@google.com>
Cc: Nicolas Dumazet <769f3f35fc5e5cb24adae4ce5839a1956ca822df@google.com>
Signed-off-by: Hannes Frederic Sowa <331be22c6b63ca3e0a03d408c2d906b1b02cd5f2@stressinduktion.org>
Signed-off-by: David S. Miller <fe08d3c717adf2ae63592e4c9aec6e3e404d8e3e@davemloft.net>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs