perf/arm-cmn: Add CMN-700 support

Add the identifiers, events, and subtleties for CMN-700. Highlights
include yet more options for doubling up CHI channels, which finally
grows event IDs beyond 8 bits for XPs, and a new set of CML gateway
nodes adding support for CXL as well as CCIX, where the Link Agent is
now internal to the CMN mesh so we gain regular PMU events for that too.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Tested-by: Ilkka Koskinen <ilkka@os.amperecomputing.com>
Link: https://lore.kernel.org/r/cf892baa0d0258ea6cd6544b15171be0069a083a.1650320598.git.robin.murphy@arm.com
Signed-off-by: Will Deacon <will@kernel.org>

Author: rmurphy-arm