ARM: OMAP2+: Move most of plat/io.h into local iomap.h

There's no need to have these defines in plat/io.h.

Note that we now need to ifdef omap_read/write calls
as they will be available for omap1 only.

While at it, clean up the includes to group them like
they typically are grouped.

Signed-off-by: Tony Lindgren <tony@atomide.com>
diff --git a/arch/arm/mach-omap2/sdrc2xxx.c b/arch/arm/mach-omap2/sdrc2xxx.c
index 791a63c..2c329a6 100644
--- a/arch/arm/mach-omap2/sdrc2xxx.c
+++ b/arch/arm/mach-omap2/sdrc2xxx.c
@@ -24,13 +24,14 @@
 #include <linux/clk.h>
 #include <linux/io.h>
 
-#include "common.h"
 #include <plat/clock.h>
 #include <plat/sram.h>
+#include <plat/sdrc.h>
 
+#include "iomap.h"
+#include "common.h"
 #include "prm2xxx_3xxx.h"
 #include "clock.h"
-#include <plat/sdrc.h>
 #include "sdrc.h"
 
 /* Memory timing, DLL mode flags */