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/t102xrdb/ddr.c b/board/freescale/t102xrdb/ddr.c
index 56f98ac..773aa77 100644
--- a/board/freescale/t102xrdb/ddr.c
+++ b/board/freescale/t102xrdb/ddr.c
@@ -229,7 +229,7 @@
 }
 #endif
 
-phys_size_t initdram(void)
+int initdram(void)
 {
 	phys_size_t dram_size;
 
@@ -249,5 +249,7 @@
 	fsl_dp_resume();
 #endif
 
-	return dram_size;
+	gd->ram_size = dram_size;
+
+	return 0;
 }