Merge branch 'mptcp-misc-features-for-v6-18'

Matthieu Baerts says:

====================
mptcp: misc. features for v6.18

This series contains 4 independent new features:

- Patch 1: use HMAC-SHA256 library instead of open-coded HMAC.

- Patch 2: selftests: check for unexpected fallback counter increments.

- Patches 3-4: record subflows in RPS table, for aRFS support.

v1: https://lore.kernel.org/20250901-net-next-mptcp-misc-feat-6-18-v1-0-80ae80d2b903@kernel.org
====================

Link: https://patch.msgid.link/20250902-net-next-mptcp-misc-feat-6-18-v2-0-fa02bb3188b1@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>