driconf: remove the redundant glx-extension-disabling options

driconf: remove the redundant glx-extension-disabling options

Now that we introduced the generic glx_extension_override option,
we can remove the glx_disable_oml_sync_control,
glx_disable_sgi_video_sync, and glx_disable_ext_buffer_age ones.

It seems like the only user for them was the vmwgfx, and only for
Gnome and Compiz which are covered by the default mesa driconf. This
means that it is unlikely for a user to have these options set in
their local driconf file.

Suggested-by: Timothy Arceri <tarceri@itsqueeze.com>
Reviewed-by: Timothy Arceri <tarceri@itsqueeze.com>
Signed-off-by: Martin Peres <martin.peres@mupuf.org>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7252>