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/rockchip/evb_rk3328/evb-rk3328.c b/board/rockchip/evb_rk3328/evb-rk3328.c
index 7e70f38..a7895cb 100644
--- a/board/rockchip/evb_rk3328/evb-rk3328.c
+++ b/board/rockchip/evb_rk3328/evb-rk3328.c
@@ -22,11 +22,13 @@
 	return 0;
 }
 
-void dram_init_banksize(void)
+int dram_init_banksize(void)
 {
 	/* Reserve 0x200000 for ATF bl31 */
 	gd->bd->bi_dram[0].start = 0x200000;
 	gd->bd->bi_dram[0].size = 0x7e000000;
+
+	return 0;
 }
 
 int usb_gadget_handle_interrupts(void)