Merge branches 'pm-docs' and 'pm-misc'

* pm-docs:
  Documentation: PM: Unify copyright notices
  Documentation: PM: Add SPDX license tags to multiple files
  cpufreq: intel_pstate: Documentation: Add references sections

* pm-misc:
  firmware/psci: add support for SYSTEM_RESET2
  drivers: firmware: psci: Announce support for OS initiated suspend mode
  drivers: firmware: psci: Simplify error path of psci_dt_init()
  drivers: firmware: psci: Split psci_dt_cpu_init_idle()
  MAINTAINERS: Update files for PSCI
  drivers: firmware: psci: Move psci to separate directory