update CPU feature macros in src/opts

Use macros from SkPreConfig.h where they exist and are appropriate.

Change-Id: If8e161ca2a105e75b76dfc75c75f91abfc5997ef
Reviewed-on: https://skia-review.googlesource.com/150963
Commit-Queue: Mike Klein <mtklein@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
Auto-Submit: Mike Klein <mtklein@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
3 files changed