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>

src/mainboard/emulation/qemu-i440fx/romstage.c

@@ -28,7 +28,7 @@
 #include <timestamp.h>
 #include "drivers/pc80/udelay_io.c"
 #include "lib/delay.c"
-#include "cpu/x86/lapic.h"
+#include <cpu/x86/lapic.h>
 
 #include "memory.c"
 

src/mainboard/emulation/qemu-q35/romstage.c

@@ -29,7 +29,7 @@
 #include <timestamp.h>
 #include "drivers/pc80/udelay_io.c"
 #include "lib/delay.c"
-#include "cpu/x86/lapic.h"
+#include <cpu/x86/lapic.h>
 
 #include "../qemu-i440fx/memory.c"