Publishing and Self-Archiving
The text you quote is from Elsevier, and their policy on hosting articles says that "arXiv and RePEc can update a preprint immediately with the accepted manuscript and a DOI link to the formal publication" (while the embargo period applies only to other organizations), so you haven't violated the agreement in updating the arXiv posting.  You can add the DOI via the arXiv's journal reference feature once it is available.