openvswitch: Merge three per-CPU structures into one

openvswitch: Merge three per-CPU structures into one

exec_actions_level is a per-CPU integer allocated at compile time.
action_fifos and flow_keys are per-CPU pointer and have their data
allocated at module init time.
There is no gain in splitting it, once the module is allocated, the
structures are allocated.

Merge the three per-CPU variables into ovs_pcpu_storage, adapt callers.

Cc: Aaron Conole <aconole@redhat.com>
Cc: Eelco Chaudron <echaudro@redhat.com>
Cc: Ilya Maximets <i.maximets@ovn.org>
Cc: dev@openvswitch.org
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Aaron Conole <aconole@redhat.com>
Link: https://patch.msgid.link/20250512092736.229935-8-bigeasy@linutronix.de
Signed-off-by: Paolo Abeni <pabeni@redhat.com>