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/sec-common.c b/arch/arm/mach-omap2/sec-common.c
index e9b3e74..f3df8af 100644
--- a/arch/arm/mach-omap2/sec-common.c
+++ b/arch/arm/mach-omap2/sec-common.c
@@ -14,6 +14,7 @@
 
 #include <common.h>
 #include <cpu_func.h>
+#include <init.h>
 #include <stdarg.h>
 
 #include <asm/arch/sys_proto.h>