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/prcm_mpu44xx.c b/arch/arm/mach-omap2/prcm_mpu44xx.c
index ca669b5..928dbd4 100644
--- a/arch/arm/mach-omap2/prcm_mpu44xx.c
+++ b/arch/arm/mach-omap2/prcm_mpu44xx.c
@@ -15,8 +15,8 @@
 #include <linux/err.h>
 #include <linux/io.h>
 
+#include "iomap.h"
 #include "common.h"
-
 #include "prcm_mpu44xx.h"
 #include "cm-regbits-44xx.h"