Add loongson3a Build jobs.

Change-Id: I4a0259f82272099e08df0e7dea91489f6d641ca4
Reviewed-on: https://skia-review.googlesource.com/113670
Commit-Queue: Ben Wagner <benjaminwagner@google.com>
Reviewed-by: Mike Klein <mtklein@chromium.org>
7 files changed