overlays: i2c-fan: add compatible for upstream compatibility

[nullr0ute]

The way upstream deals with compatibles is to add emc2305 and then deal with the variations in the driver as it's detectable so add emc2305 to the compat so we work with the upstream driver.

[nullr0ute]

FYI: the upstream driver looks in a better state recently.

[pelwell]

Tailoring the Device Tree to match the Linux driver implementation seems to go against the upstream DT rules.

[6by9]

Tailoring the Device Tree to match the Linux driver implementation seems to go against the upstream DT rules.

It's as required by the bindings
https://github.com/torvalds/linux/blob/master/Documentation/devicetree/bindings/hwmon/microchip%2Cemc2305.yaml#L21-L26

  compatible:
    oneOf:
      - enum:
          - microchip,emc2305
      - items:
          - enum:
              - microchip,emc2303
              - microchip,emc2302
              - microchip,emc2301
          - const: microchip,emc2305

It's using emc2305 as the fallback that the driver picks up.
Should some issue be discovered with emc2301 that can't be handled by autodetection, then microchip,emc2301 gets added to the driver as a specific compatible with whatever special handling is required.

LGTM.

[pelwell]

I should have been more explicit: I think the upstream driver is breaking the principles of OS-neutral DT files.