ARM: dts: AM3XXX: Use #include for all device trees

Replace /include/ by #include for AM33XX and AM35XX device tree
files, in order to use the C pre-processor, making use of #define
features possible.

Signed-off-by: Florian Vaussard <florian.vaussard@epfl.ch>
Tested-by: Afzal Mohammed <afzal@ti.com>
Signed-off-by: Benoit Cousson <benoit.cousson@linaro.org>

arch/arm/boot/dts/am335x-bone.dts

@@ -7,7 +7,7 @@
  */
 /dts-v1/;
 
-/include/ "am33xx.dtsi"
+#include "am33xx.dtsi"
 
 / {
 	model = "TI AM335x BeagleBone";