Add missing methods to neon/sse SkNx implementations

Adds negate, abs, sqrt to Sk2f and/or Sk4f.

Bug: skia:
Change-Id: I0688dae45b32ff94abcc0525ef1f09d666f9c6e9
Reviewed-on: https://skia-review.googlesource.com/39642
Reviewed-by: Mike Klein <mtklein@chromium.org>
Commit-Queue: Chris Dalton <csmartdalton@google.com>
3 files changed