net: dpaa_eth: simplify dpaa_ioctl()

net: dpaa_eth: simplify dpaa_ioctl()

phylink_mii_ioctl() handles multiple ioctls in addition to just
SIOCGMIIREG: SIOCGMIIPHY, SIOCSMIIREG. Don't filter these out.

Also, phylink can handle the case where net_dev->phydev is NULL (like
optical SFP module, fixed-link). Be like other drivers and let phylink
do so without any driver-side call filtering.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>
Acked-by: Madalin Bucur <madalin.bucur@oss.nxp.com>
Link: https://patch.msgid.link/20250508124753.1492742-4-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>