tcp: Build RACK and BBR stacks as a part of LINT

When RACK and BBR were added to the kernel, they were put
behind 'WITH_EXTRA_TCP_STACKS=1'. Unfortunately that was
never added to any NOTES file, so RACK & BBR were not compiled
with the various LINT-NOINET, LINT-NOINET6, and LINT-NOIP kernels.
This lead to the stacks sometimes being broken.

This change:

• Fixes RACK so that it compiles with the various LINT-NO* kernels
• Adds WITH_EXTRA_TCP_STACKS=1 to all NOTES kernels so that RACK and BBR are compile tested regularly

Sponsored by: Netflix
Reviewed by: rrs
Differential Revision: https://reviews.freebsd.org/D37903