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/arch/mips/mach-pic32/include/mach/ddr.h b/arch/mips/mach-pic32/include/mach/ddr.h
index 00abfa3..e7da807 100644
--- a/arch/mips/mach-pic32/include/mach/ddr.h
+++ b/arch/mips/mach-pic32/include/mach/ddr.h
@@ -8,7 +8,7 @@
 #ifndef __MICROCHIP_PIC32_DDR_H
 #define __MICROCHIP_PIC32_DDR_H
 
-/* called by initdram() function */
+/* called by dram_init() function */
 void ddr2_phy_init(void);
 void ddr2_ctrl_init(void);
 phys_size_t ddr2_calculate_size(void);