SMP: Add arch-agnostic boot_cpu()

We should not have x86 specific includes in lib/.

Change-Id: I18fa9c8017d65c166ffd465038d71f35b30d6f3d
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: http://review.coreboot.org/5156
Tested-by: build bot (Jenkins)
Reviewed-by: David Hendricks <dhendrix@chromium.org>
Reviewed-by: Aaron Durbin <adurbin@google.com>

src/include/smp/node.h

@@ -0,0 +1,10 @@
+#ifndef _SMP_NODE_H_
+#define _SMP_NODE_H_
+
+#if CONFIG_SMP
+int boot_cpu(void);
+#else
+#define boot_cpu(x) 1
+#endif
+
+#endif /* _SMP_NODE_H_ */