Rename gn options to skgpu_v1 and skgpu_v2

Bug: skia:11837
Change-Id: Ie9221d2cd8e42bebb6a8a9a8ef51ba4a488ce6ca
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/424036
Reviewed-by: Greg Daniel <egdaniel@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>
10 files changed