Re-add IntelIris640 Linux bots.

These were removed in
https://skia-review.googlesource.com/c/skia/+/78640
However, we've now decided on the 640 rather than the 540 due to
inventory.

No-Try: true
Change-Id: Icf6db636287e151d3dd3ac74cfddf8f6bd3bea6a
Reviewed-on: https://skia-review.googlesource.com/87202
Reviewed-by: Kevin Lubick <kjlubick@google.com>
Commit-Queue: Ben Wagner <benjaminwagner@google.com>
5 files changed