release: Add AZURE to CLOUDWARE

Let Azure use the image directly built by the release engineering team.

Reviewed by: emaste
Approved by: cperciva (re)
MFC after: 3 days
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D41906

(cherry picked from commit 63007e46110d7f7a1f9d48fbac99f8a5bc166456)