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/arch/arm/mach-davinci/misc.c b/arch/arm/mach-davinci/misc.c
index e699d61..e1064e0 100644
--- a/arch/arm/mach-davinci/misc.c
+++ b/arch/arm/mach-davinci/misc.c
@@ -28,10 +28,12 @@
 	return 0;
 }
 
-void dram_init_banksize(void)
+int dram_init_banksize(void)
 {
 	gd->bd->bi_dram[0].start = CONFIG_SYS_SDRAM_BASE;
 	gd->bd->bi_dram[0].size = gd->ram_size;
+
+	return 0;
 }
 #endif