board_f: Drop return value from initdram()

At present we cannot use this function as an init sequence call without a
wrapper, since it returns the RAM size. Adjust it to set the RAM size in
global_data instead, and return 0 on success.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Stefan Roese <sr@denx.de>
diff --git a/board/freescale/m5253demo/m5253demo.c b/board/freescale/m5253demo/m5253demo.c
index fef2ca6..1c100e6 100644
--- a/board/freescale/m5253demo/m5253demo.c
+++ b/board/freescale/m5253demo/m5253demo.c
@@ -13,6 +13,8 @@
 #include <netdev.h>
 #include <asm/io.h>
 
+DECLARE_GLOBAL_DATA_PTR;
+
 int checkboard(void)
 {
 	puts("Board: ");
@@ -20,7 +22,7 @@
 	return 0;
 };
 
-phys_size_t initdram(void)
+int initdram(void)
 {
 	u32 dramsize = 0;
 
@@ -73,7 +75,9 @@
 		mb();
 	}
 
-	return dramsize;
+	gd->ram_size = dramsize;
+
+	return 0;
 }
 
 int testdram(void)