Demonstration of Complete Device Tree

This blueprint tracks the work required to implement and demonstrate
full device tree support for an SoC family. This differs from the
work described in tr-kernel-dt-board-desc-n-implementation[1] in that
this work is to describing the internal details of an SoC family,
while tr-kernel-dt-board-desc-n-implementation covers describing the
board and the connections to the SoC.

[1] https://blueprints.launchpad.net/linaro/+spec/tr-kernel-dt-board-desc-n-implementation/

The purpose of this work is to investigate the tasks required to fully
describe an SoC using the devices tree, and to evaluate how 'deeply' a
device tree description should describe the internals of an SoC
family. The goal is to be able to provide good recommendations to SoC
subarch maintainers about how and when to put SoC internal details
into the device tree bindings.

Work items:
Select an SoC family for this demonstration: TODO
Implement board support work items from [1] for selected SoC family: TODO
Implement common struct clk changes for selected SoC family: TODO
Draft and implement DT bindings for SoC clock device: TODO
Instantiate clock tree from DT data: TODO
Draft and implement DT bindings for SoC power management: TODO
Instantiate power management objects from DT data: TODO
Remove static device registrations (platform, i2c, spi, etc) and register devices from DT: TODO
Review resulting patches and document recommended practises: TODO