compat: add SCTP netfilter states for older kernels

compat: add SCTP netfilter states for older kernels

Bake in the SCTP states from the kernel UAPI.  This means an older
revision of the kernel headers won't interfere with the SCTP display
enhancement.  Additionally, if a newer version is available, or if
x-compiling the datapath module we defer to that version (since this
is just meant to provide the missing definitions).

This will be used in a future commit.

Signed-off-by: Aaron Conole <aconole@redhat.com>
Signed-off-by: Ben Pfaff <blp@ovn.org>