remove private copy of SkM44.h

Change-Id: Ifd47b929bafd40d190722366a0c1e2b856220ab3
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/272836
Reviewed-by: Florin Malita <fmalita@chromium.org>
Commit-Queue: Mike Reed <reed@google.com>
2 files changed