ACPI: scan: add stub acpi_create_platform_device() for !CONFIG_ACPI

It adds a stub acpi_create_platform_device() for !CONFIG_ACPI build, so
that caller doesn't have to deal with !CONFIG_ACPI build issue.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>