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/micronas/vct/vct.c b/board/micronas/vct/vct.c
index 02824ea..8bf8d5f 100644
--- a/board/micronas/vct/vct.c
+++ b/board/micronas/vct/vct.c
@@ -61,7 +61,7 @@
  * SDRAM is already configured by the bootstrap code, only return the
  * auto-detected size here
  */
-int initdram(void)
+int dram_init(void)
 {
 	gd->ram_size = get_ram_size((long *)CONFIG_SYS_SDRAM_BASE,
 			    CONFIG_SYS_MBYTES_SDRAM << 20);