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>
diff --git a/board/freescale/ls2080a/ddr.c b/board/freescale/ls2080a/ddr.c
index 0bff922..d340c41 100644
--- a/board/freescale/ls2080a/ddr.c
+++ b/board/freescale/ls2080a/ddr.c
@@ -158,14 +158,12 @@
 	return 0;
 }
 #endif
-phys_size_t initdram(void)
+int initdram(void)
 {
-	phys_size_t dram_size;
-
 	puts("Initializing DDR....");
 
 	puts("using SPD\n");
-	dram_size = fsl_ddr_sdram();
+	gd->ram_size = fsl_ddr_sdram();
 
-	return dram_size;
+	return 0;
 }