common: Move ARM cache operations out of common.h

These functions are CPU-related and do not use driver model. Move them to
cpu_func.h

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
diff --git a/board/sandbox/sandbox.c b/board/sandbox/sandbox.c
index 9ca1eca..438f9a4 100644
--- a/board/sandbox/sandbox.c
+++ b/board/sandbox/sandbox.c
@@ -4,6 +4,7 @@
  */
 
 #include <common.h>
+#include <cpu_func.h>
 #include <cros_ec.h>
 #include <dm.h>
 #include <led.h>