Add an option to keep the ROM cached after romstage

Change-Id: I05f1cbd33f0cb7d80ec90c636d1607774b4a74ef
Signed-off-by: Stefan Reinauer <reinauer@google.com>
Reviewed-on: http://review.coreboot.org/739
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>

src/cpu/x86/lapic/boot_cpu.c

@@ -1,7 +1,8 @@
+#include <cpu/x86/lapic.h>
 #include <cpu/x86/msr.h>
 
 #if CONFIG_SMP
-static int boot_cpu(void)
+int boot_cpu(void)
 {
 	int bsp;
 	msr_t msr;