[POWERPC] 85xx: some minor cleanups for stx_gp3 and tqm85xx

* "simple-bus" covers all our needs for of_platform_bus_probe()
* make device tree name just 'soc' not 'soc85..'

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
diff --git a/arch/powerpc/boot/dts/tqm8540.dts b/arch/powerpc/boot/dts/tqm8540.dts
index a6e3989..1addb3a 100644
--- a/arch/powerpc/boot/dts/tqm8540.dts
+++ b/arch/powerpc/boot/dts/tqm8540.dts
@@ -48,7 +48,7 @@
 		reg = <0x00000000 0x10000000>;
 	};
 
-	soc8540@e0000000 {
+	soc@e0000000 {
 		#address-cells = <1>;
 		#size-cells = <1>;
 		device_type = "soc";