dt-bindings: interconnect: qcom,msm8998-cpu-bwmon: add BWMON device

Add bindings for the Qualcomm Bandwidth Monitor device providing
performance data on interconnects.  The bindings describe only BWMON CPU
(version 4), e.g. the instance which appeared for the first on Qualcomm
MSM8998 SoC and is also used on SDM845.  This BWMON device sits between
CPU and Last Level Cache Controller.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Acked-by: Georgi Djakov <djakov@kernel.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20220704121730.127925-2-krzysztof.kozlowski@linaro.org