soc: qcom: llcc: Add missing description for members in slice config

Fix all warnings thrown due to missing description for some of the
members in llcc_slice_config.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202312050519.mup4Q8mD-lkp@intel.com/


Signed-off-by: Abel Vesa <abel.vesa@linaro.org>
Link: https://lore.kernel.org/r/20231205-llcc-fix-slice-config-warnings-v1-1-d6331d601dd3@linaro.org


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