KWIML: Teach ABI.h about OpenRISC 1000

It defines __or1k__ and is big endian.
Merge branch 'upstream-kwiml' into update-kwiml
Merge topic 'update-kwiml' into next

45ab21ee Merge branch 'upstream-kwiml' into update-kwiml
3c0bb281 KWIML: Teach ABI.h about OpenRISC 1000