sh_eth: cleanup 'enum TD_STS_BIT'

Fix the comment to 'enum TD_STS_BIT', reformat the values, and add a couple of
values missing before (though unused by the driver).

Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: David S. Miller <davem@davemloft.net>