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/arch/powerpc/cpu/mpc83xx/spd_sdram.c b/arch/powerpc/cpu/mpc83xx/spd_sdram.c
index 08918a9..a14a438 100644
--- a/arch/powerpc/cpu/mpc83xx/spd_sdram.c
+++ b/arch/powerpc/cpu/mpc83xx/spd_sdram.c
@@ -13,6 +13,7 @@
 #ifndef CONFIG_MPC83XX_SDRAM
 
 #include <common.h>
+#include <cpu_func.h>
 #include <vsprintf.h>
 #include <asm/processor.h>
 #include <asm/io.h>