psp: report basic stats from the core

psp: report basic stats from the core

Track and report stats common to all psp devices from the core. A
'stale-event' is when the core marks the rx state of an active
psp_assoc as incapable of authenticating psp encapsulated data.

Signed-off-by: Daniel Zahka <daniel.zahka@gmail.com>
Link: https://patch.msgid.link/20251106002608.1578518-2-daniel.zahka@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>