board_f: Drop return value from initdram()

At present we cannot use this function as an init sequence call without a
wrapper, since it returns the RAM size. Adjust it to set the RAM size in
global_data instead, and return 0 on success.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Stefan Roese <sr@denx.de>

board/freescale/t4rdb/ddr.c

@@ -105,7 +105,7 @@ found:
 	popts->cpo_sample = 0x64;
 }
 
-phys_size_t initdram(void)
+int initdram(void)
 {
 	phys_size_t dram_size;
 
@@ -120,5 +120,7 @@ phys_size_t initdram(void)
 	dram_size = setup_ddr_tlbs(dram_size / 0x100000);
 	dram_size *= 0x100000;
 
-	return dram_size;
+	gd->ram_size = dram_size;
+
+	return 0;
 }