Revert "added support for sk_ClipDistance"

This reverts commit 8b8c76506a9a3b07246e6c2770e35dfc413da97a.

Reason for revert: breaks Vulkan

Original change's description:
> added support for sk_ClipDistance
> 
> Change-Id: I14fd921cace23ab37a1e5e9d5da94d92d3688680
> Reviewed-on: https://skia-review.googlesource.com/8225
> Reviewed-by: Chris Dalton <csmartdalton@google.com>
> Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
> 

TBR=csmartdalton@google.com,ethannicholas@google.com,reviews@skia.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Change-Id: I84d6bc75738eb9a8e090aa60e6421f2437a027b2
Reviewed-on: https://skia-review.googlesource.com/8246
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
5 files changed