arm/dt: msm: Move I/O devices to a dedicated SoC node

The Device Tree specification suggests that memory-mapped
I/O devices should be declared within the 'soc' node rather
than being declared at the root level. Refactor the MSM
device tree files to follow to this design pattern.

Furthermore, declaring I/O devices with the 'soc' node
facilitates reuse of common DTSI files across device trees
whose root-level #address-cells and #size-cells properties
might be different.

Explicitly call of_platform_populate on the /soc node to
parent its devices to the root node, to preserve the kernel
ABI until userspace is updated.

Change-Id: Ib6a4a42c3a3d419b5f8d8c49706ed5d78c1b6adc
Signed-off-by: Stepan Moskovchenko <stepanm@codeaurora.org>
diff --git a/arch/arm/boot/dts/msm8610-bus.dtsi b/arch/arm/boot/dts/msm8610-bus.dtsi
index 50066f3..2e7ba25 100644
--- a/arch/arm/boot/dts/msm8610-bus.dtsi
+++ b/arch/arm/boot/dts/msm8610-bus.dtsi
@@ -10,7 +10,7 @@
  * GNU General Public License for more details.
  */
 
-/ {
+&soc {
 	msm-mmss-noc@fc478000 {
 		compatible = "msm-bus-fabric";
 		reg = <0xfc478000 0x00004000>;