add missing license line to SkVM_opts.h

Change-Id: Ie66eccaae13bd1499b3b21bd1bc3c08f867e58aa
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/276139
Auto-Submit: Mike Klein <mtklein@google.com>
Reviewed-by: Herb Derby <herb@google.com>
Commit-Queue: Mike Klein <mtklein@google.com>
1 file changed