board_f: Rename initdram() to dram_init()

This allows us to use the same DRAM init function on all archs. Add a
dummy function for arc, which does not use DRAM init here.

Signed-off-by: Simon Glass <sjg@chromium.org>
[trini: Dummy function on nios2]
Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/board/freescale/m53017evb/m53017evb.c b/board/freescale/m53017evb/m53017evb.c
index b0c27b4..71cca35 100644
--- a/board/freescale/m53017evb/m53017evb.c
+++ b/board/freescale/m53017evb/m53017evb.c
@@ -22,7 +22,7 @@
 	return 0;
 };
 
-int initdram(void)
+int dram_init(void)
 {
 	sdram_t *sdram = (sdram_t *)(MMAP_SDRAM);
 	u32 dramsize, i;