ACPI / scan: Allow platform device creation without any IO resources

Currently, ACPI platform device creation is aborted when there
are no valid IO resources for the device.  This approach will not
work if the device has only GPIO as its resource or some custom
resources.

Remove zero resource check and allow platform device creation even
without any valid IO resources.

[rjw: Changelog]
Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>