egl/x11: authenticate before doing chipset id ioctls

egl/x11: authenticate before doing chipset id ioctls

For systems without udev or sysfs that use drm ioctls in the loader
drm authentication must take place earlier or the loader will fail
"MESA-LOADER: failed to get param for i915".

Patch from Mark Kettenis.

Cc: "11.2 11.1" <mesa-stable@lists.freedesktop.org>
Signed-off-by: Mark Kettenis <kettenis@openbsd.org>
Signed-off-by: Jonathan Gray <jsg@jsg.id.au>
[Emil Velikov: remove gratuitous white-space]
Reviewed-by: Emil Velikov <emil.velikov@collabora.com>