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/arch/arm/mach-omap2/emif-common.c b/arch/arm/mach-omap2/emif-common.c
index c900f28..bb81063 100644
--- a/arch/arm/mach-omap2/emif-common.c
+++ b/arch/arm/mach-omap2/emif-common.c
@@ -9,6 +9,7 @@
  */
 
 #include <common.h>
+#include <init.h>
 #include <net.h>
 #include <asm/emif.h>
 #include <asm/arch/clock.h>