ARM: dts: lpc32xx: phy3250: add NAND partitions device node

To declare MTD OF partitions NAND controller device node should have
a special 'partitions' subnode, the change removes a debug message
from mtd/ofpart on boot:

  nxp_lpc3220_slc: 'partitions' subnode not found on /ahb/flash@20020000.
  Trying to parse direct subnodes as partitions.
Acked-by: Sylvain Lemieux <slemieux.tyco@gmail.com>
Signed-off-by: Vladimir Zapolskiy <vz@mleia.com>

arch/arm/boot/dts/phy3250.dts

@@ -136,8 +136,6 @@ &sd {
 
 /* 64MB Flash via SLC NAND controller */
 &slc {
-	#address-cells = <1>;
-	#size-cells = <1>;
 	status = "okay";
 
 	nxp,wdr-clks = <14>;
@@ -151,6 +149,11 @@ &slc {
 	nand-on-flash-bbt;
 	gpios = <&gpio 5 19 1>; /* GPO_P3 19, active low */
 
+	partitions {
+		compatible = "fixed-partitions";
+		#address-cells = <1>;
+		#size-cells = <1>;
+
 		mtd0@00000000 {
 			label = "phy3250-boot";
 			reg = <0x00000000 0x00064000>;
@@ -177,6 +180,7 @@ mtd4@00604000 {
 			label = "phy3250-rootfs";
 			reg = <0x00604000 0x039fc000>;
 		};
+	};
 };
 
 &ssp0 {