This patch adds support for cacheinfo on ARM64.

On ARMv8, the cache hierarchy can be identified through Cache Level ID
(CLIDR) register while the cache geometry is provided by Cache Size ID
(CCSIDR) register.

Since the architecture doesn't provide any way of detecting the cpus
sharing particular cache, device tree is used for the same purpose.
Signed-off-by: NSudeep Holla <sudeep.holla@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>