perf: arm-ccn: Enable stats for CCN-512 interconnect

Add compatible string for the ARM CCN-512 interconnect

Acked-by: Pawel Moll <pawel.moll@arm.com>
Signed-off-by: Marek Bykowski <marek.bykowski@gmail.com>
Signed-off-by: Boleslaw Malecki <boleslaw.malecki@tieto.com>
Signed-off-by: Will Deacon <will@kernel.org>