net: dpaa2-mac: allow lynx PCS to manage mdiodev lifetime

commit  894ccb7e3f8342423e0145010f60263d08ccbcc5 from
https://github.com/nxp-imx/linux-imx lf-6.1.y

Put the mdiodev after lynx_pcs_create() so that the Lynx PCS driver
can manage the lifetime of the mdiodev its using.

Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
(cherry picked from commit 6c79a9c8

)
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Xiaolei Wang <xiaolei.wang@windriver.com>