Switch to generated //modules/skcms/skcms.gni.

Derive //modules/skcms/skcms.gni from the Bazel project files.
See //bazel/exporter_tool/README.md

Bug: skia:13485
Change-Id: I31ecad1eb3c4e3f08e96d238c1ca4c43606fa9b3
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/578637
Commit-Queue: Chris Mumford <cmumford@google.com>
Reviewed-by: Kevin Lubick <kjlubick@google.com>
3 files changed