common: Move older CPU functions to their own header

These should be moved to driver model, but in the meantime, move them
out of the common header to help reduce its size.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Tom Rini <trini@konsulko.com>

cmd/mp.c

@@ -5,6 +5,7 @@
 
 #include <common.h>
 #include <command.h>
+#include <cpu_func.h>
 
 static int cpu_status_all(void)
 {