backend/drm: rename to KMS
"DRM" is a Linux kernel subsystem which handles both rendering and display. DRM is responsible for both driving the 3D engine and the display engine of modern GPUs.
Thus, "DRM" is a bit confusing to use as a backend name. DRM is used by all hardware-accelerated renderers. Other backends may use DRM constructs like DRM devices, drm_syncobj
, and so on.
"KMS" is the name of the DRM subsystem responsible for display.