move skcms impl into skcms.c

This makes everyone a unity build, and ought to make it easier to switch
to C++.  There are lots of things to clean up now that everything is in
a single file canonically, mostly functions in skcms_internal.h that can
become static instead.  That will be the next CL (or next couple).

Change-Id: Ia957611f5c893399723718d4a23d4d40ea5478b2
Reviewed-on: https://skia-review.googlesource.com/138931
Commit-Queue: Mike Klein <mtklein@chromium.org>
Auto-Submit: Mike Klein <mtklein@chromium.org>
Reviewed-by: Brian Osman <brianosman@google.com>
9 files changed