Remove SkPM4fPriv.h, inline the two functions at call-sites

Bug: skia:
Change-Id: I8e4dd56441a42f3f367a22cc0be943839bd5f4d2
Reviewed-on: https://skia-review.googlesource.com/c/165305
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
4 files changed