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/imgtec/xilfpga/xilfpga.c b/board/imgtec/xilfpga/xilfpga.c
index 77a1952..dc0a088 100644
--- a/board/imgtec/xilfpga/xilfpga.c
+++ b/board/imgtec/xilfpga/xilfpga.c
@@ -12,7 +12,7 @@
 #include <common.h>
 
 /* initialize the DDR Controller and PHY */
-phys_size_t initdram(int board_type)
+phys_size_t initdram(void)
 {
 	/* MIG IP block is smart and doesn't need SW
 	 * to do any init */