Move SkColorPriv from include to src

We don't want this to leak into usage. Major clients have been updated.

Change-Id: I4039a374b0aca002d55a6be6292d5def26d8bd1d
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/962277
Reviewed-by: Florin Malita <fmalita@google.com>
Commit-Queue: Kaylee Lubick <kjlubick@google.com>
79 files changed