perfmon: make less arch dependent

perfmon: make less arch dependent

In preparation for enabling perfmon on Arm platforms, move some Intel
/arch specific logic into the /intel directory and update the CMake to
split the common code from arch specific files.

Since the dispatch_wrapper code is very different on Arm/Intel,
each arch can provide their own implementation + conduct any additional
arch specific config e.g. on Intel, all indexes from the mmap pages are
cached. The new method intel_config_dispatch_wrapper conducts this
config and returns a pointer to the dispatch wrapper to use.

Similarly, is_bundle_supported() looks very different on Arm/Intel, so
each implementation is to provide their own arch specific checks.

Two new callbacks/function ptrs are added in PERFMON_REGISTER_SOURCE to
support this - .bundle_support and .config_dispatch_wrapper.

Type: refactor
Signed-off-by: Zachary Leaf <zachary.leaf@arm.com>
Change-Id: Idd121ddcfd1cc80a57c949cecd64eb2db0ac8be3