Add CPU dimension for MacMini7.1.

No-Try: true
Change-Id: Ia55bb4bf1e4de5167ed181f4dfcde9210e7a447c
Reviewed-on: https://skia-review.googlesource.com/106024
Reviewed-by: Eric Boren <borenet@google.com>
Commit-Queue: Ben Wagner <benjaminwagner@google.com>
2 files changed