mostly pointless rename

I've learned that Bazel supports .bazel suffixes on BUILD and WORKSPACE.
Had I known this earlier I probably would not have renamed build/ to
ninja/, but now that it's that way I think it's fine to leave ninja/
alone.

So this change just makes it very clear what files are here for Bazel,
the ones with a .bazel suffix.

Change-Id: I7f3250ab680b297c17ae915fbab5bf67fb7d7929
Reviewed-on: https://skia-review.googlesource.com/c/skcms/+/316473
Reviewed-by: Joe Gregorio <jcgregorio@google.com>
Commit-Queue: Mike Klein <mtklein@google.com>
diff --git a/BUILD b/BUILD.bazel
similarity index 100%
rename from BUILD
rename to BUILD.bazel
diff --git a/WORKSPACE b/WORKSPACE.bazel
similarity index 100%
rename from WORKSPACE
rename to WORKSPACE.bazel