dri3: Enable GLX_MESA_query_renderer on DRI3 too

dri3: Enable GLX_MESA_query_renderer on DRI3 too

This should have happend around the time of commit 4680d23, but Keith's
DRI3 patches and my GLX_MESA_query_renderer patches crossed in the mail.

I don't have a working DRI3 setup, so I haven't been able to actually
verify this.  I'm hoping that someone can piglit this for me on DRI3...
It's also unfortunate the DRI2 and DRI3 can't share more code.

Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
Cc: Keith Packard <keithp@keithp.com>
Cc: "10.1" <mesa-stable@lists.freedesktop.org>
Reviewed-by: Emil Velikov <emil.l.velikov@gmail.com>