Change GrProgramInfo::visitProxies to "visitFPProxies"

We are removing dynamic state from the ProgramInfo, so the Ops will
need to invoke visits on their own primProc proxies.

Change-Id: I7ab227ab71208b7c7bcb7a9deb56b9abd556d6aa
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/277236
Commit-Queue: Chris Dalton <csmartdalton@google.com>
Reviewed-by: Robert Phillips <robertphillips@google.com>
16 files changed