net: lpc_eth: fix format warnings of block comments

Fix the following format warning:
1. Block comments use * on subsequent lines
2. Block comments use a trailing */ on a separate line

Signed-off-by: Yangyang Li <liyangyang20@huawei.com>
Signed-off-by: Weihang Li <liweihang@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>