Convert color data to skvx::float4 from Sk4f

Change-Id: I511f6105537b24953de1533ad7b73d1186afd4fc
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/541060
Commit-Queue: Michael Ludwig <michaelludwig@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
21 files changed