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/plat-omap/sram.c b/arch/arm/plat-omap/sram.c
index 4243bdc..3022fc2 100644
--- a/arch/arm/plat-omap/sram.c
+++ b/arch/arm/plat-omap/sram.c
@@ -31,11 +31,10 @@
 
 #include "sram.h"
 
-/* XXX These "sideways" includes are a sign that something is wrong */
-#if defined(CONFIG_ARCH_OMAP2) || defined(CONFIG_ARCH_OMAP3)
-# include "../mach-omap2/prm2xxx_3xxx.h"
-# include "../mach-omap2/sdrc.h"
-#endif
+/* XXX These "sideways" includes will disappear when sram.c becomes a driver */
+#include "../mach-omap2/iomap.h"
+#include "../mach-omap2/prm2xxx_3xxx.h"
+#include "../mach-omap2/sdrc.h"
 
 #define OMAP1_SRAM_PA		0x20000000
 #define OMAP2_SRAM_PUB_PA	(OMAP2_SRAM_PA + 0xf800)