run avx512 builds on Linux machines that support it

Change-Id: Iddd79c1e26e627f6c1244a3525e538cc91adf68c
Reviewed-on: https://skia-review.googlesource.com/c/skcms/+/197828
Commit-Queue: Brian Osman <brianosman@google.com>
Auto-Submit: Mike Klein <mtklein@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
1 file changed