Remove legacy RP bicubic code

Google3 and chromium have both updated, so this is unused

Cq-Include-Trybots: luci.skia.skia.primary:Canary-Chromium,Canary-G3
Change-Id: I1e6abe0db90a7163f222cc4243e68485b6b2f925
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/521839
Reviewed-by: Herb Derby <herb@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
2 files changed