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/arch/arc/lib/reset.c b/arch/arc/lib/reset.c
index 02e08df..30dd4b5 100644
--- a/arch/arc/lib/reset.c
+++ b/arch/arc/lib/reset.c
@@ -5,6 +5,7 @@
 
 #include <command.h>
 #include <common.h>
+#include <cpu_func.h>
 
 __weak void reset_cpu(ulong addr)
 {