soc/intel/common: Bring DISPLAY_MTRRS into the light

Initially, I wanted to move only the Kconfig DISPLAY_MTRRS into the
"Debug" menu. It turned out, though, that the code looks rather generic.
No need to hide it in soc/intel/.

To not bloat src/Kconfig up any further, start a new `Kconfig.debug`
hierarchy just for debug options.

If somebody wants to review the code if it's 100% generic, we could
even get rid of HAVE_DISPLAY_MTRRS.

Change-Id: Ibd0a64121bd6e4ab5d7fd835f3ac25d3f5011f24
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.coreboot.org/c/29684
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/drivers/intel/fsp2_0/notify.c b/src/drivers/intel/fsp2_0/notify.c
index c3a2804..a5c7ef0 100644
--- a/src/drivers/intel/fsp2_0/notify.c
+++ b/src/drivers/intel/fsp2_0/notify.c
@@ -12,8 +12,8 @@
 
 #include <bootstate.h>
 #include <console/console.h>
+#include <cpu/x86/mtrr.h>
 #include <fsp/util.h>
-#include <soc/intel/common/util.h>
 #include <string.h>
 #include <timestamp.h>
 
@@ -70,9 +70,7 @@
 {
 	enum fsp_notify_phase phase = (uint32_t)arg;
 
-	/* Display the MTRRs */
-	if (IS_ENABLED(CONFIG_DISPLAY_MTRRS))
-		soc_display_mtrrs();
+	display_mtrrs();
 
 	fsp_notify(phase);
 	if (phase == READY_TO_BOOT)