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/drivers/intel/fsp2_0/Kconfig

@@ -16,7 +16,6 @@
 config PLATFORM_USES_FSP2_0
 	bool
 	select UDK_2015_BINDING
-	select HAVE_LINEAR_FRAMEBUFFER
 	help
 	  Include FSP 2.0 wrappers and functionality
 

src/drivers/intel/fsp2_0/Makefile.inc

@@ -27,7 +27,7 @@ romstage-$(CONFIG_CACHE_RELOCATED_RAMSTAGE_OUTSIDE_CBMEM) += stage_cache.c
 romstage-$(CONFIG_MMA) += mma_core.c
 
 ramstage-y += debug.c
-ramstage-y += graphics.c
+ramstage-$(CONFIG_RUN_FSP_GOP) += graphics.c
 ramstage-y += hand_off_block.c
 ramstage-$(CONFIG_DISPLAY_FSP_HEADER) += header_display.c
 ramstage-$(CONFIG_DISPLAY_HOBS) += hob_display.c

src/drivers/intel/fsp2_0/include/fsp/util.h

@@ -85,7 +85,11 @@ enum cb_err fsp_validate_component(struct fsp_header *hdr,
 					const struct region_device *rdev);
 
 /* Load a vbt.bin file for graphics. Returns 0 if a valid VBT is not found. */
+#if IS_ENABLED(CONFIG_RUN_FSP_GOP)
 uintptr_t fsp_load_vbt(void);
+#else
+static inline uintptr_t fsp_load_vbt(void) { return 0; }
+#endif
 
 /* Get igd framebuffer bar from SoC */
 uintptr_t fsp_soc_get_igd_bar(void);