common: Move RAM-sizing functions to init.h

These functions relate to memory init so move them into the init
header.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/board/tqc/tqm834x/tqm834x.c b/board/tqc/tqm834x/tqm834x.c
index 95f95a5..02b3d2d 100644
--- a/board/tqc/tqm834x/tqm834x.c
+++ b/board/tqc/tqm834x/tqm834x.c
@@ -6,6 +6,7 @@
 
 #include <common.h>
 #include <fdt_support.h>
+#include <init.h>
 #include <ioports.h>
 #include <mpc83xx.h>
 #include <asm/mpc8349_pci.h>