arm64: dts: qcom: sm8550: switch to interrupt-cells 4 to add PPI partitions

arm64: dts: qcom: sm8550: switch to interrupt-cells 4 to add PPI partitions

The ARM PMUs shares the same per-cpu (PPI) interrupt, so we need to switch
to interrupt-cells = <4> in the GIC node to allow adding an interrupt
partition map phandle as the 4th cell value for GIC_PPI interrupts.

Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://lore.kernel.org/r/20250820-topic-sm8550-upstream-pmu-ppi-4-cells-v1-1-a8915672e996@linaro.org
Signed-off-by: Bjorn Andersson <andersson@kernel.org>