egl/sl: use drmDevice API to enumerate available devices

This provides for a more comprehensive iteration and slightly more
straight-forward codebase.

v2:
 - s/dpy/disp/
 - keep original 64 devices (Eric)

Signed-off-by: Emil Velikov <emil.velikov@collabora.com>
Reviewed-by: Eric Engestrom <eric.engestrom@intel.com>
Reviewed-by: Mathias Fröhlich <Mathias.Froehlich@web.de>
Reviewed-by: Gurchetan Singh <gurchetansingh@chromium.org>
1 file changed