drm/msm/sde: add support for 8-level qos lut

QoS LUT is used to control bus priority of sspp & wb.
sdm845 extends this to 8-level. Add support for
8-level QoS LUT, and add corresponding fill-level
QoS tables to device tree.

CRs-Fixed: 2037879
Change-Id: Ib7a74ee2bdad0396904d32e14c79def9bd542503
Signed-off-by: Alan Kwong <akwong@codeaurora.org>