drm/msm/dpu: remove RM topology definition

RM maintained a redundant definition for display topology
to identify the no. of hw blocks needed for a display
and their hardware dependencies. This information can be
implicitly deduced from the msm_display_topology structure
available in RM reserve request. In addition to getting
rid of the redundant topology, this change also removes
the topology name enums and their usages.

changes in v4:
	- remove the topology name enum entirely (Sean)
changes in v5:
	- remove RM topology definition and their
	  references (Sean)
	- Implement helper for dual mixer CRTC (Sean)
changes in v6:
	- avoid heap memory for topology (Sean)

Signed-off-by: Jeykumar Sankaran <jsanka@codeaurora.org>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Rob Clark <robdclark@gmail.com>