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/x86/cpu/broadwell/sdram.c b/arch/x86/cpu/broadwell/sdram.c
index 74736cd..774aba6 100644
--- a/arch/x86/cpu/broadwell/sdram.c
+++ b/arch/x86/cpu/broadwell/sdram.c
@@ -28,9 +28,11 @@
 	return mrc_common_board_get_usable_ram_top(total_size);
 }
 
-void dram_init_banksize(void)
+int dram_init_banksize(void)
 {
 	mrc_common_dram_init_banksize();
+
+	return 0;
 }
 
 void broadwell_fill_pei_data(struct pei_data *pei_data)