serial HLG support

The gamma part of the curve is looking great.
The log part of the curve isn't _quite_ perfect.

Bug: chromium:960620
Change-Id: Id0fab23a632ad24f27d7248d9902df06e3a23226
Reviewed-on: https://skia-review.googlesource.com/c/skcms/+/247722
Commit-Queue: Brian Osman <brianosman@google.com>
Auto-Submit: Mike Klein <mtklein@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
2 files changed