dt-bindings: interconnect: qcom-bwmon: Document QCS615 bwmon compatibles

Document QCS615 BWMONs, which includes one BWMONv4 instance for CPU to
LLCC path bandwidth monitoring and one BWMONv5 instance for LLCC to DDR
path bandwidth monitoring.

Signed-off-by: Lijuan Gao <quic_lijuang@quicinc.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20241218-add_bwmon_support_for_qcs615-v1-1-680d798a19e5@quicinc.com


Signed-off-by: Bjorn Andersson <andersson@kernel.org>