Merge branches 'acpi-scan', 'acpi-glue', 'acpi-bus' and 'acpi-sysfs'

Merge ACPI support infrastructure changes for 7.4:

 - Make the core ACPI device enumeration code stop attempting to
   initialize ACPI power management for devices before they are
   known to be present and functional (Rafael Wysocki)

 - Simplify and clean up the core ACPI device enumeration code on top of
   the previous adjustment and reduce debug noise coming from it (Rafael
   Wysocki)

 - Fix locking in the code binding devices to their ACPI companions,
   prevent it from replacing a valid ACPI companion pointer with NULL
   incidentally, improve its messaging (including debug noise
   reduction), and reduce its overhead by making it skip the cases in
   which no ACPI companion may exist early (Rafael Wysocki)

 - Reduce runtime memory footprint of struct acpi_device by rearranging
   fields in it (Andy Shevchenko)

 - Update the driver core to allow bus types without drivers to be
   registered as "companion bus types" without driver-related sysfs
   attributes and register the ACPI bus type as a companion one (Rafael
   Wysocki)

 - Use strscpy() instead of strcpy() in the ACPI sysfs interface (Ruslan
   Vagner)

* acpi-scan:
  ACPI: scan: Combine two conditionals in acpi_bus_attach()
  ACPI: PM: Move acpi_bus_init_power() declaration to internal header file
  ACPI: scan: Stop calling acpi_bus_init_power() early
  ACPI: PM: Drop parent state update from acpi_device_get_power()
  ACPI: scan: Drop useless and noisy debug statement

* acpi-glue:
  ACPI: glue: Skip devices with no type in acpi_device_notify()
  ACPI: glue: Fix up and adjust acpi_unbind_one()
  ACPI: glue: Rearrange acpi_bind_one() to avoid breakage
  ACPI: glue: Carry out companion lookup under bus_type_sem
  ACPI: glue: Rework the success message in acpi_device_notify()
  ACPI: glue: Reduce debug noise from acpi_device_notify()

* acpi-bus:
  driver core/ACPI: Introduce companion_bus_register()
  ACPI: bus: Reduce runtime memory footprint of struct acpi_device

* acpi-sysfs:
  ACPI: sysfs: use strscpy() instead of strcpy()