GL: Extend disable of EXT_clip_control to Mali-G51. The G51 appears to be the only other device with this issue. Bug: chromium:1434317 Change-Id: Iffbc95a7f612c1862e9d129649a6211f488df6c9 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/4706564 Commit-Queue: Colin Blundell <blundell@chromium.org> Reviewed-by: Colin Blundell <blundell@chromium.org>