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/amcc/sequoia/sdram.c b/board/amcc/sequoia/sdram.c
index 9bedb5b..ea98717 100644
--- a/board/amcc/sequoia/sdram.c
+++ b/board/amcc/sequoia/sdram.c
@@ -30,10 +30,10 @@
 
 /*************************************************************************
  *
- * initdram -- 440EPx's DDR controller is a DENALI Core
+ * dram_init -- 440EPx's DDR controller is a DENALI Core
  *
  ************************************************************************/
-int initdram(void)
+int dram_init(void)
 {
 #if !defined(CONFIG_SYS_RAMBOOT)
 	ulong speed = get_bus_freq(0);