common: Move checkcpu() out of common.h

This function belongs in cpu_func.h so move it over.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Tom Rini <trini@konsulko.com>
diff --git a/arch/x86/cpu/ivybridge/cpu.c b/arch/x86/cpu/ivybridge/cpu.c
index 6db9da8..8f30cdb 100644
--- a/arch/x86/cpu/ivybridge/cpu.c
+++ b/arch/x86/cpu/ivybridge/cpu.c
@@ -11,6 +11,7 @@
  */
 
 #include <common.h>
+#include <cpu_func.h>
 #include <dm.h>
 #include <errno.h>
 #include <fdtdec.h>