ACPI: Drop the container.h header file

The include/acpi/container.h only contains a definition of a
structure that is not used any more, so drop it entirely.

Similar change was proposed earlier by Toshi Kani.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Toshi Kani <toshi.kani@hp.com>
Merge branch 'acpi-cleanup-next' into bleeding-edge

* acpi-cleanup-next:
  ACPI: Drop the container.h header file