dt-bindings: arm: Catch up with Cortex/Neoverse CPUs again

Add bindings for the 2020 and 2021 cohorts of Cortex-A and Neoverse
CPUs, now featuring their Cortex-X cousins as well.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/a36014d06d308c73d3fa1ed55e8967fb8adadf0d.1638900542.git.robin.murphy@arm.com


Signed-off-by: Rob Herring <robh@kernel.org>