net: phy: mscc: fix copyright and author information in MACsec

All headers in the MSCC PHY driver have been copied and pasted from the
original mscc.c file. However the information is not necessarily
correct, as in the MACsec support. Fix this.

Signed-off-by: Antoine Tenart <antoine.tenart@bootlin.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>