fsp/gop: Add running the GOP to the choice of gfx init

The new config choice is called RUN_FSP_GOP. Some things had to happen
on the road:

  * Drop confusing config GOP_SUPPORT,
  * Add HAVE_FSP_GOP to chipsets that support it,
  * Make running the GOP an option for FSP2.0 by returning 0
    in random VBT getters.

Change-Id: I92f88424004a4c0abf1f39cc02e2a146bddbcedf
Signed-off-by: Nico Huber <nico.huber@secunet.com>
Reviewed-on: https://review.coreboot.org/19815
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

Documentation/Intel/Board/board.html

@@ -72,7 +72,6 @@
       <li>Set the CPU_MICROCODE_CBFS_LOC</li>
       <li>Set the FSP_IMAGE_ID_STRING</li>
       <li>Set the FSP_LOC</li>
-      <li>Disable GOP_SUPPORT</li>
       <li>No payload</li>
       <li>Choose the default value for all other options</li>
     </ol>