Merge branches 'pm-core', 'pm-qos' and 'pm-docs'

* pm-core:
  PM: core: Fix device_pm_check_callbacks()

* pm-qos:
  PM / QoS: Use the correct variable to check the QoS request type

* pm-docs:
  PM: docs: Drop an excess character from devices.rst
  driver core: Fix link to device power management documentation