net: seeq: fix crash caused by not set dev.parent

The old MIPS implementation of dma_cache_sync() didn't use the dev argument,
but commit c9eb6172

 ("dma-mapping: turn dma_cache_sync into a
dma_map_ops method") changed that, so we now need to set dev.parent.

Signed-off-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
Signed-off-by: David S. Miller <davem@davemloft.net>