Add separate --internal argument to get all internal repos from
playground, regardless what --device is used.

Change-Id: If0411f877d1c7c21fcc7a4ac7f03adec3dabd5f6
Reviewed-by: Teemu Holappa <teemu.holappa@theqtcompany.com>
Reviewed-by: Louai Al-Khanji <louai.al-khanji@theqtcompany.com>