powerpc/e6500: Include Power ISA properties

b4420 and b4860 device trees do not have these properties.
Signed-off-by: NLijun Pan <Lijun.Pan@freescale.com>
Signed-off-by: NScott Wood <scottwood@freescale.com>

arch/powerpc/boot/dts/fsl/b4420si-pre.dtsi

@@ -34,6 +34,8 @@
 
 /dts-v1/;
 
+/include/ "e6500_power_isa.dtsi"
+
 / {
 	compatible = "fsl,B4420";
 	#address-cells = <2>;

arch/powerpc/boot/dts/fsl/b4860si-pre.dtsi

@@ -34,6 +34,8 @@
 
 /dts-v1/;
 
+/include/ "e6500_power_isa.dtsi"
+
 / {
 	compatible = "fsl,B4860";
 	#address-cells = <2>;