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/pdm360ng/pdm360ng.c b/board/pdm360ng/pdm360ng.c
index ef19daf..c833aec 100644
--- a/board/pdm360ng/pdm360ng.c
+++ b/board/pdm360ng/pdm360ng.c
@@ -48,7 +48,7 @@
 	},
 };
 
-phys_size_t initdram(void)
+int initdram(void)
 {
 	int i;
 	u32 msize = 0;
@@ -95,7 +95,9 @@
 			break;
 	}
 
-	return msize;
+	gd->ram_size = msize;
+
+	return 0;
 }
 
 static int set_lcd_brightness(char *);