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/cadence/xtfpga/xtfpga.c b/board/cadence/xtfpga/xtfpga.c
index 5899aa6..39b9b12 100644
--- a/board/cadence/xtfpga/xtfpga.c
+++ b/board/cadence/xtfpga/xtfpga.c
@@ -48,10 +48,12 @@
 	return 0;
 }
 
-void dram_init_banksize(void)
+int dram_init_banksize(void)
 {
 	gd->bd->bi_memstart = PHYSADDR(CONFIG_SYS_SDRAM_BASE);
 	gd->bd->bi_memsize = CONFIG_SYS_SDRAM_SIZE;
+
+	return 0;
 }
 
 int board_postclk_init(void)