cleaned up ISO code usage for Kurdish, fdo#63460

* instead of the 'ku' macrolanguage code use proper ISO 639-3 codes and
  use 'Latn' script with 'kmr'
* use MS-LCID 0x0492 for Central Kurdish (Iraq) [ckb-IQ]
* added Southern Kurdish (Iraq) [sdh-IQ]

Change-Id: Iaee8be98d0659a0e7bbf041e60025dd1f771066f