tcp stacks: in kernel BBR and RACK require in kernel HPTS

Compiling the BBR or RACK stack into the kernel requires HPTS to be
compiled into the kernel.

Reviewed by: glebius, rscheff
Sponsored by: Netflix, Inc.
Differential Revision: https://reviews.freebsd.org/D42998

(cherry picked from commit 793e4aca9e70f2441f0f4e1688d0a727d602ed81)