Merge branch 'neighbour-misc-follow-ups-on-per-netns-neigh_table-series'

Kuniyuki Iwashima says:

====================
neighbour: Misc follow-ups on per-netns neigh_table series.

Patch 1 updates the switchdev doc, s/arp_tbl/arp_table(net)/.

Patch 2 updates a selftest for per-netns sysctl knobs, though this
is not an actual issue since the test does not hit gc_thresh by
default.

Patches 3 ~ 5 are based on a suggestion by Ido Schimmel to make
neigh_periodic_work() and neigh_managed_work() CPU-friendly:

  https://lore.kernel.org/netdev/20260902143023.GA3966681@shredder/
====================

Link: https://patch.msgid.link/20261013205816.1642597-1-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>