board_f: Drop board_type parameter from initdram()

It looks like only cm5200 and tqm8xx use this feature, so we don't really
need it in generic code. Drop it and have the users access gd->board_type
directly.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Stefan Roese <sr@denx.de>
diff --git a/board/freescale/mpc5121ads/mpc5121ads.c b/board/freescale/mpc5121ads/mpc5121ads.c
index 7c44282..e134091 100644
--- a/board/freescale/mpc5121ads/mpc5121ads.c
+++ b/board/freescale/mpc5121ads/mpc5121ads.c
@@ -95,7 +95,7 @@
 	return(ismicron);
 }
 
-phys_size_t initdram(int board_type)
+phys_size_t initdram(void)
 {
 	u32 msize = 0;
 	/*