drm/msm: add split voting support to sde power handle

Split voting allows separate votes to be applied for
each section of bus paths. This allows better
optimization on bus voting. Add new data bus
identifiers to describe new bus voting topology.
Rename CRTC bandwidth control properties to dram_ab
and dram_ib to better reflect the underlying
hardware being controlled.

CRs-Fixed: 2037879
Change-Id: I43224d3a9cd75334bc8d1031c3eb9b8286d1a376
Signed-off-by: Alan Kwong <akwong@codeaurora.org>