arm64: dts: arm: juno: Remove legacy Coresight 'slave-mode' property

arm64: dts: arm: juno: Remove legacy Coresight 'slave-mode' property

The 'slave-mode' property is not valid under 'in-ports' as it was the
legacy way to find input ports. Warnings are generated from the Coresight
schema:

arch/arm64/boot/dts/arm/juno-r1.dtb: funnel@20150000: in-ports:port@0:endpoint: Unevaluated properties are not allowed ('slave-mode' was unexpected)
        From schema: Documentation/devicetree/bindings/arm/arm,coresight-dynamic-funnel.yaml

Link: https://lore.kernel.org/r/20220721212952.1984382-1-robh@kernel.org
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>