dt-bindings: media: allwinner, sun4i-a10-ir: Add R40 compatible

Allwinner R40 has very similar IR core to that found in A31.

Add compatible for R40 and while at it, sort compatibles by family.

Signed-off-by: Jernej Skrabec <jernej.skrabec@siol.net>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/20200825171358.1286902-2-jernej.skrabec@siol.net