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>

src/device/Kconfig

@@ -33,6 +33,12 @@ config HAVE_LINEAR_FRAMEBUFFER
 	  Selected by graphics drivers that can set up a generic linear
 	  framebuffer.
 
+config HAVE_FSP_GOP
+	bool
+	help
+	  Selected by drivers that support to run a blob that implements
+	  the Graphics Output Protocol (GOP).
+
 config MAINBOARD_HAS_NATIVE_VGA_INIT
 	def_bool n
 	help
@@ -76,6 +82,15 @@ config MAINBOARD_USE_LIBGFXINIT
 	  Use the SPARK library `libgfxinit` for the native graphics
 	  initialization. This requires an Ada toolchain.
 
+config RUN_FSP_GOP
+	bool "Run a GOP driver"
+	depends on HAVE_FSP_GOP
+	select HAVE_LINEAR_FRAMEBUFFER
+	help
+	  Some platforms (e.g. Intel Braswell and Skylake/Kaby Lake) support
+	  to run a GOP blob. This option enables graphics initialization with
+	  such a blob.
+
 # TODO: Explain differences (if any) for onboard cards.
 config VGA_ROM_RUN
 	bool "Run VGA Option ROMs"