Remove SkYUVAPixmapInfo::SupportedDataTypes(const GrImageContext&)

This has been moved to private because it is unused externally (AFAIK)
and we want to decouple src/core and the GPU backend.

Change-Id: I00fa395c95cf7379093703d1ca5ebe428e3cbd98
Bug: skia:14317
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/710901
Owners-Override: Kevin Lubick <kjlubick@google.com>
Reviewed-by: Jim Van Verth <jvanverth@google.com>
Commit-Queue: Kevin Lubick <kjlubick@google.com>
8 files changed