Revert "CHROMIUM: Reset tree to 'mesa-21.1.0-rc1'"

This reverts commit 635d557a0a5ae027ad6cbc93367afdfa8905449d.

Reason for revert: Suspected to cause virtio-video errors

Original change's description:
> CHROMIUM: Reset tree to 'mesa-21.1.0-rc1'
>
> Change-Id: I6023c905034989036eeb8d107cfffa309dadd855

Bug: b:187659256
Test: git diff 98ccf7d4c85
Change-Id: I13ab37b58d36dd5f45a85e130db1354aabf2d7bd
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/mesa/+/2886470
Reviewed-by: Chung-Sheng Wu <chungsheng@chromium.org>
Tested-by: Shuhei Takahashi <nya@chromium.org>
Owners-Override: Shuhei Takahashi <nya@chromium.org>
Commit-Queue: Shuhei Takahashi <nya@chromium.org>
4096 files changed