i965: Explicitly disallow tiled memcpy path on Gen4 with swizzling.

i965: Explicitly disallow tiled memcpy path on Gen4 with swizzling.

The manual detiling paths are not prepared to handle Gen4-G45 with
swizzling enabled, so explicitly disable them.  (They're already
disabled because these platforms don't have LLC but a future patch could
enable this path).

Reviewed-by: Matt Turner <mattst88@gmail.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Kenneth Graunke <kenneth@whitecape.org>