arm64: dts: sdm845: Add device node for Last level cache controller

Last level cache (aka. system cache) controller provides control
over the last level cache present on SDM845. This cache lies after
the memory noc, right before the DDR.

Signed-off-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>
Signed-off-by: Vivek Gautam <vivek.gautam@codeaurora.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>