change matrix_2x3 to row-major

Change-Id: Id25b3875f54f359bac90b6d3a7695287fc108b64
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/456467
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Herb Derby <herb@google.com>
4 files changed