dt-bindings/perf: Add Arm NI-700 PMU

Add an initial binding for the Arm NI-700 interconnect PMU. As with the
Arm CMN family, there are already future NI products on the roadmap, so
the overall binding is named generically just in case any
non-discoverable incompatibility between generations crops up.

Cc: devicetree@vger.kernel.org
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/5f86237580219116de37e5e54d8b7eb0c9ed580d.1725470837.git.robin.murphy@arm.com


Signed-off-by: Will Deacon <will@kernel.org>