driver: net: fsl-mc: remove unused strcture elements

driver: net: fsl-mc: remove unused strcture elements

The phydev structure is present in both ldpaa_eth_priv and
wriop_dpmac_info. the phydev in wriop_dpmac_info is not being used

As the phydev is created based on phy_addr and bus members of
wriop_dpmac_info, it is appropriate to keep phydev in wriop_dpmac_info.

Also phy_regs is not being used, therefore remove it

Signed-off-by: Pankaj Bansal <pankaj.bansal@nxp.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>