ohci-/ehci-platform: Change compatible string to ?hci-platform

[Arnd Bergmann]

On Tuesday 11 February 2014 10:27:12 Alan Stern wrote:
> 
> It might even be a good idea to change the "xhci-platform" string to 
> match, it that doesn't cause too much trouble.

The original xhci binding was contributed by Al Cooper, but I don't
see any dts files using it. I agree that xhci-generic is a better
name than xhci-platform, and I think we should make that the recommended
string. If Al or someone thinks the xhci-generic string might already
be used in production devices, we should however allow both names
in the binding and in the driver.

	Arnd