Absolutely no connection whatsoever.
Celtic FC and their fans claim roots from oppressed Irish Catholics. So they tend to support any other rebellious cause around the world, as long as they are not anti-catholic. Hence their support for the IRA, Basques, Hamas, Palestinians, Che Guvara, etc. Likewise they hate the perceived oppressors; Britain, Israel, USA, etc.
As a Norseman you will not be welcome because of your country's Protestant roots.