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/intercontrol/digsy_mtc/digsy_mtc.c b/board/intercontrol/digsy_mtc/digsy_mtc.c
index 922d9ef..b8bc045 100644
--- a/board/intercontrol/digsy_mtc/digsy_mtc.c
+++ b/board/intercontrol/digsy_mtc/digsy_mtc.c
@@ -74,12 +74,12 @@
 #endif
 
 /*
- * ATTENTION: Although partially referenced initdram does NOT make real use
+ * ATTENTION: Although partially referenced dram_init does NOT make real use
  *            use of CONFIG_SYS_SDRAM_BASE. The code does not work if
  *            CONFIG_SYS_SDRAM_BASE is something other than 0x00000000.
  */
 
-int initdram(void)
+int dram_init(void)
 {
 	ulong dramsize = 0;
 	ulong dramsize2 = 0;