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>

post/cpu/mpc83xx/ecc.c

@@ -9,6 +9,7 @@
  */
 
 #include <common.h>
+#include <cpu_func.h>
 #include <mpc83xx.h>
 #include <watchdog.h>
 #include <asm/io.h>

post/lib_powerpc/cpu.c

@@ -5,6 +5,7 @@
  */
 
 #include <common.h>
+#include <cpu_func.h>
 
 /*
  * CPU test