multiple drivers for same hardware

[Kumar Gala]

We have some scenarios in which we might have 2 different drivers (one in kernel or one user space as an example) and wanted to see how we'd convey in the device tree which driver should "claim" the specific device instance.

From glancing at the OF specs it seems we could utilize the precedence order of compatible as a means to specify.  So something like:

[ bind with UIO instead of standard driver ]

	compatible = "gianfar-lnx-uio", "gianfar";

vs [ bind with stock kernel driver ]
	compatible = "gianfar";

The other thought I had was introducing a new property like:

	linux-drv = "gianfar-uio";
	compatible = "gianfar";

thoughts?

- k