ARM: OMAP2+ Move SoC specific headers to be local to mach-omap2

These can now be moved to be local headers in mach-omap2.

Note that this patch removes arch/arm/plat-omap/devices.c as it
will get removed anyways with Paul Walmsley's patch
"ARM: OMAP: split OMAP1, OMAP2+ RNG device registration".

Signed-off-by: Tony Lindgren <tony@atomide.com>

arch/arm/mach-omap2/omap-mpuss-lowpower.c

@@ -50,9 +50,8 @@
 #include <asm/suspend.h>
 #include <asm/hardware/cache-l2x0.h>
 
-#include <plat/omap44xx.h>
-
 #include "common.h"
+#include "omap44xx.h"
 #include "omap4-sar-layout.h"
 #include "pm.h"
 #include "prcm_mpu44xx.h"