ui/console: move dcl compatiblity check to a callback

ui/console: move dcl compatiblity check to a callback

As expected from the "compatible_dcl" comment, a simple comparison of
ops isn't enough. The following patch will fix a regression introduced
by this limited check by extending the compatibility callback for
egl-headless.

For now, this patch simply replaces the the "compatible_dcl" ops pointer
with a "dpy_gl_ctx_is_compatible_ctx" callback.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>