Add the obvious compatible name to the existing IR binding, and pair
it with the existing A31 fallback compatible string, as the devices
are compatible.

On the way use enums to group all compatible devices together.
Signed-off-by: NAndre Przywara <andre.przywara@arm.com>
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NSean Young <sean@mess.org>
Signed-off-by: NMauro Carvalho Chehab <mchehab+huawei@kernel.org>