soc: qcom: llcc: Add write-cache cacheable support

Newer SoCs with LLCC IP version 2.1.0.0 and later support write
sub-cache cacheable feature. Use a separate llcc_slice_config member
"write_scid_cacheable_en" to identify this feature and program
LLCC_TRP_SCID_WRSC_CACHEABLE_EN register to enable it.

Signed-off-by: Sai Prakash Ranjan <quic_saipraka@quicinc.com>
Tested-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/83372c8178f579d055ec58212ce5af5d55abadd4.1643355594.git.quic_saipraka@quicinc.com