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>

board/qemu-mips/qemu-mips.c

@@ -13,7 +13,7 @@
 
 DECLARE_GLOBAL_DATA_PTR;
 
-int initdram(void)
+int dram_init(void)
 {
 	/* Sdram is setup by assembler code */
 	/* If memory could be changed, we should return the true value here */