Revert of Temporarily limit x86 SIMD to SSE2 only, to see effect on all benches and bots. (https://codereview.chromium.org/331193004/)

Reason for revert:
Experiment is over: disabling SSSE3 is a 25-50% perf regression for bitmap scaling on every machine we've got.

Original issue's description:
> Temporarily limit x86 SIMD to SSE2 only, to see effect on all benches and bots.
>
> BUG=372232
>
> Committed: https://skia.googlesource.com/skia/+/f1e5a04832e4d350f9ebf5d556c6d3897345f883

R=reed@google.com, mtklein@chromium.org
TBR=mtklein@chromium.org, reed@google.com
NOTREECHECKS=true
NOTRY=true
BUG=372232

Author: mtklein@google.com

Review URL: https://codereview.chromium.org/332213005
1 file changed