common: Move some cache and MMU functions out of common.h

These functions belong in cpu_func.h. Another option would be cache.h
but that code uses driver model and we have not moved these cache
functions to use driver model. Since they are CPU-related it seems
reasonable to put them here.

Move them over.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Tom Rini <trini@konsulko.com>
diff --git a/board/toradex/colibri_pxa270/colibri_pxa270.c b/board/toradex/colibri_pxa270/colibri_pxa270.c
index e9e1750..c4db516 100644
--- a/board/toradex/colibri_pxa270/colibri_pxa270.c
+++ b/board/toradex/colibri_pxa270/colibri_pxa270.c
@@ -7,6 +7,7 @@
  */
 
 #include <common.h>
+#include <cpu_func.h>
 #include <dm.h>
 #include <asm/arch/hardware.h>
 #include <asm/arch/pxa.h>