Include boot_cpu.c for romstage builds

ROMCC boards were left unmodified.

Change-Id: I3d842196b3f5b6999b6891b914036e9ffcc3cef0
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: http://review.coreboot.org/3853
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <patrick@georgi-clan.de>

src/cpu/x86/lapic/Makefile.inc

@@ -3,4 +3,5 @@ ramstage-y += lapic_cpu_init.c
 ramstage-y += secondary.S
 romstage-$(CONFIG_UDELAY_LAPIC) += apic_timer.c
 ramstage-$(CONFIG_UDELAY_LAPIC) += apic_timer.c
+romstage-y += boot_cpu.c
 ramstage-y += boot_cpu.c

src/cpu/x86/lapic/boot_cpu.c

@@ -10,7 +10,5 @@ int boot_cpu(void)
 	bsp = !!(msr.lo & (1 << 8));
 	return bsp;
 }
-#else
-#define boot_cpu(x) 1
 #endif