coresight: Add support for trace filtering by source

coresight: Add support for trace filtering by source

Some replicators have hard coded filtering of "trace" data, based on the
source device. This is different from the trace filtering based on
TraceID, available in the standard programmable replicators. e.g.,
Qualcomm replicators have filtering based on custom trace protocol
format and is not programmable.

The source device could be connected to the replicator via intermediate
components (e.g., a funnel). Thus we need platform information from
the firmware tables to decide the source device corresponding to a
given output port from the replicator. Given this affects "trace
path building" and traversing the path back from the sink to source,
add the concept of "filtering by source" to the generic coresight
connection.

The specified source will be marked like below in the Devicetree.
test-replicator {
    ... ... ... ...
    out-ports {
        ... ... ... ...
        port@0 {
            reg = <0>;
            xyz: endpoint {
                remote-endpoint = <&zyx>;
                filter-source = <&source_1>; <-- To specify the source to
            };                           be filtered out here.
        };

        port@1 {
            reg = <1>;
            abc: endpoint {
                remote-endpoint = <&cba>;
                filter-source = <&source_2>; <-- To specify the source to
            };                           be filtered out here.
        };
    };
};

Signed-off-by: Tao Zhang <quic_taozha@quicinc.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20241213100731.25914-4-quic_taozha@quicinc.com