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/freescale/mx53smd/mx53smd.c b/board/freescale/mx53smd/mx53smd.c
index 938c611..630d671 100644
--- a/board/freescale/mx53smd/mx53smd.c
+++ b/board/freescale/mx53smd/mx53smd.c
@@ -30,13 +30,15 @@
 
 	return 0;
 }
-void dram_init_banksize(void)
+int dram_init_banksize(void)
 {
 	gd->bd->bi_dram[0].start = PHYS_SDRAM_1;
 	gd->bd->bi_dram[0].size = PHYS_SDRAM_1_SIZE;
 
 	gd->bd->bi_dram[1].start = PHYS_SDRAM_2;
 	gd->bd->bi_dram[1].size = PHYS_SDRAM_2_SIZE;
+
+	return 0;
 }
 
 #define UART_PAD_CTRL	(PAD_CTL_HYS | PAD_CTL_DSE_HIGH | \