move encoders into codec_srcs

This is a stepping stone towards runtime registration.

This should work in concert with all the other CLs
that are in the roll pipeline to get things building.

Change-Id: Id95f1e0bbea2f48f7b5fa438f4310f8db1d5b978
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/214083
Auto-Submit: Mike Klein <mtklein@google.com>
Reviewed-by: Mike Klein <mtklein@google.com>
Commit-Queue: Mike Klein <mtklein@google.com>
1 file changed