Device Tree bindings for clkdev

The clk subsystem does not feature device tree bindings for clkdev (the part that maps clocks to devices using name lookups), meaning that all clkdev implementations there will tie clocks to a predefined device name (the string you get from dev_name(&dev)).

This in turn means that the devices cannot have their names assigned from the device tree, or the clock lookups will fail.

Currently systems using device tree with clkdev will assign names to their devices using AUXDATA just to get the string in place that the clkdev lookup needs.

What is needed to properly solve this situation is common clkdev DT bindings so that devices can just reference the clkdev node in the tree and the clk subsystem will resolve this.