drm/msm/sde: add basic sde object enumeration

Implement basic crtc, encoder, and plane support that
implements DRM atomic call sequence, queries hardware, and
enumerates resources as DRM objects. This includes basic
color format support, as well as querying of displays
to create appropriate encoders, crtcs. Also includes
supporting clock control logic.

Change-Id: I25a9c74b92262d81986b3441c89d51bff2d14dbb
Signed-off-by: Abhijit Kulkarni <kabhijit@codeaurora.org>