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/display.c b/arch/arm/mach-omap2/display.c
index 3677b1f..28d16a4 100644
--- a/arch/arm/mach-omap2/display.c
+++ b/arch/arm/mach-omap2/display.c
@@ -30,6 +30,7 @@
 #include <plat/omap-pm.h>
 #include "common.h"
 
+#include "iomap.h"
 #include "mux.h"
 #include "control.h"
 #include "display.h"