common: Move reset_cpu() to the CPU header

Move this function out of common.h and into a relevant header file.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/cmd/tpm_test.c b/cmd/tpm_test.c
index c14dd75..2cde517 100644
--- a/cmd/tpm_test.c
+++ b/cmd/tpm_test.c
@@ -5,6 +5,7 @@
 
 #include <common.h>
 #include <command.h>
+#include <cpu_func.h>
 #include <tpm-v1.h>
 #include "tpm-user-utils.h"