PM: EM: Rename em.yaml to dev-energymodel.yaml

PM: EM: Rename em.yaml to dev-energymodel.yaml

The EM YNL specification used many acronyms, including ‘em’, ‘pd’,
‘ps’, etc. While the acronyms are short and convenient, they could be
confusing. So, let’s spell them out to be more specific. The following
changes were made in the spec. Note that the protocol name cannot exceed
GENL_NAMSIZ (16).

  em           -> dev-energymodel
  pds          -> perf-domains
  pd           -> perf-domain
  pd-id        -> perf-domain-id
  pd-table     -> perf-table
  ps           -> perf-state
  get-pds      -> get-perf-domains
  get-pd-table -> get-perf-table
  pd-created   -> perf-domain-created
  pd-updated   -> perf-domain-updated
  pd-deleted   -> perf-domain-deleted

In addition. doc strings were added to the spec. based on the comments in
energy_model.h. Two flag attributes (perf-state-flags and
perf-domain-flags) were added for easily interpreting the bit flags.

Finally, the autogenerated files and em_netlink.c were updated accordingly
to reflect the name changes.

Suggested-by: Donald Hunter <donald.hunter@gmail.com>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Reviewed-by: Donald Hunter <donald.hunter@gmail.com>
Signed-off-by: Changwoo Min <changwoo@igalia.com>
Link: https://patch.msgid.link/20260108053212.642478-3-changwoo@igalia.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>