Using `#include "drm.h"` instead of `#include <drm/drm.h>` allow drm
headers to be moved in another directory without changes, like for the
libdrm imports.
Signed-off-by: NGabriel Laskar <gabriel@lse.epita.fr>
Reviewed-by: NEmil Velikov <emil.l.velikov@gmail.com>
CC: Emil Velikov <emil.l.velikov@gmail.com>
CC: Mikko Rapeli <mikko.rapeli@iki.fi>