arm: dts: lpc32xx: change include syntax to be C preprocessor friendly

The change replaces /include/ to #include in lpc32xx.dtsi and
derivatives, it is required, if C preprocessor is intended to be used
over dtsi/dts files, otherwise errors like one below are generated:

  Error: ea3250.dts:15.1-9 syntax error
  FATAL ERROR: Unable to parse input tree
Signed-off-by: Vladimir Zapolskiy <vz@mleia.com>

arch/arm/boot/dts/ea3250.dts

@@ -12,7 +12,7 @@
  */
 
 /dts-v1/;
-/include/ "lpc32xx.dtsi"
+#include "lpc32xx.dtsi"
 
 / {
 	model = "Embedded Artists LPC3250 board based on NXP LPC3250";

arch/arm/boot/dts/lpc32xx.dtsi

@@ -11,7 +11,7 @@
  * http://www.gnu.org/copyleft/gpl.html
  */
 
-/include/ "skeleton.dtsi"
+#include "skeleton.dtsi"
 
 / {
 	compatible = "nxp,lpc3220";

arch/arm/boot/dts/phy3250.dts

@@ -12,7 +12,7 @@
  */
 
 /dts-v1/;
-/include/ "lpc32xx.dtsi"
+#include "lpc32xx.dtsi"
 
 / {
 	model = "PHYTEC phyCORE-LPC3250 board based on NXP LPC3250";