Don't call CreateDisplayPipe until the display is actually needed

[seanpaul] Changed title from "DrmResources::CreateDisplayPipe throws meaningless error for DRM_MODE_DISCONNECTED"

Hi, the issue has been communicated but not tracked in gitlab nor resolved. Here it is as a kind reminder, because amdgpu, nouveau and all discrete gpus are affected.

... 2245  2245 E hwc-drm-resources: Could not find a suitable encoder/crtc for display 2
... 2245  2245 E hwc-drm-resources: Failed CreateDisplayPipe 56 with -19
... 2245  2245 E hwcomposer-drm: Can't initialize Drm object -19

Updated proposed commit to solve this problem is [1] as it is assessed that either the drm_hwcomposer code is flawed to return error for DRM_MODE_DISCONNECTED, or, in any case, it is necessary to identify E2E root cause of the problem.

Mauro Rossi

[1] https://github.com/maurossi/drm_hwcomposer/commit/027a1bf233589349761c49714defea82cd28951d