mainboard/*/romstage.c: Sanitize system header inclusions

Fix system include paths to be consistent. Chipset support is
part of the Coreboot 'system' and hence 'non-local' (i.e., in
the same directory or context). One possible product of this, is
to perhaps allow future work to do pre-compiled headers (PCH) on
the buildbot for faster build times. However, this currently just
makes mainboard's consistent.

Change-Id: I2f3fd8a3d7864926461c960ca619bff635d7dea5
Signed-off-by: Edward O'Callaghan <eocallaghan@alterapraxis.com>
Reviewed-on: http://review.coreboot.org/8085
Tested-by: build bot (Jenkins)
Reviewed-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
diff --git a/src/mainboard/intel/mtarvon/romstage.c b/src/mainboard/intel/mtarvon/romstage.c
index 959beab..61f9a2c 100644
--- a/src/mainboard/intel/mtarvon/romstage.c
+++ b/src/mainboard/intel/mtarvon/romstage.c
@@ -28,10 +28,10 @@
 #include <console/console.h>
 #include "southbridge/intel/i3100/early_smbus.c"
 #include "southbridge/intel/i3100/early_lpc.c"
-#include "northbridge/intel/i3100/raminit.h"
+#include <northbridge/intel/i3100/raminit.h>
 #include <superio/intel/i3100/i3100.h>
 #include "northbridge/intel/i3100/memory_initialized.c"
-#include "cpu/x86/bist.h"
+#include <cpu/x86/bist.h>
 #include <spd.h>
 
 #define DEVPRES_CONFIG  (DEVPRES_D1F0 | DEVPRES_D2F0)