nios2: zap initdram

Zap initdram(), as it is not used.

Signed-off-by: Thomas Chou <thomas@wytron.com.tw>
Acked-by: Marek Vasut <marex@denx.de>
diff --git a/board/altera/nios2-generic/nios2-generic.c b/board/altera/nios2-generic/nios2-generic.c
index 1f10821..e7fecd2 100644
--- a/board/altera/nios2-generic/nios2-generic.c
+++ b/board/altera/nios2-generic/nios2-generic.c
@@ -44,11 +44,6 @@
 	return 0;
 }
 
-phys_size_t initdram(int board_type)
-{
-	return 0;
-}
-
 #ifdef CONFIG_CMD_NET
 int board_eth_init(bd_t *bis)
 {