dt-bindings: msm: Update documentation of qcom,llcc

Add reg-names and interrupts for LLCC documentation and the usage
examples. llcc broadcast base is added in addition to llcc base,
which is used for llcc broadcast writes.

Signed-off-by: Venkata Narendra Kumar Gutta <vnkgutta@codeaurora.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Andy Gross <andy.gross@linaro.org>