board_f: Drop setup_dram_config() wrapper

By making dram_init_banksize() return an error code we can drop the
wrapper. Adjust this and clean up all implementations.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Stefan Roese <sr@denx.de>
diff --git a/board/samsung/arndale/arndale.c b/board/samsung/arndale/arndale.c
index 881d080..405ed3b 100644
--- a/board/samsung/arndale/arndale.c
+++ b/board/samsung/arndale/arndale.c
@@ -55,7 +55,7 @@
 	return 0;
 }
 
-void dram_init_banksize(void)
+int dram_init_banksize(void)
 {
 	int i;
 	u32 addr, size;
@@ -67,6 +67,8 @@
 		gd->bd->bi_dram[i].start = addr;
 		gd->bd->bi_dram[i].size = size;
 	}
+
+	return 0;
 }
 
 #ifdef CONFIG_GENERIC_MMC