soc: qcom: Rename llcc-slice to llcc-qcom

The cleaning up was done without changing the driver file name
to ensure a cleaner bisect. Change the file name now to facilitate
making the driver generic in subsequent patch.

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