net: phy: dp83867: introduce critical chip default init for non-of platform

PHY driver dp83867 has rich supports for OF-platform to fine-tune the PHY
chip during phy configuration. However, for non-OF platform, certain PHY
tunable parameters such as IO impedance and RX & TX internal delays are
critical and should be initialized to its default during PHY driver probe.

Tested-by: Clement <clement@intel.com>
Signed-off-by: Lay, Kuan Loon <kuan.loon.lay@intel.com>
Co-developed-by: Ong Boon Leong <boon.leong.ong@intel.com>
Signed-off-by: Ong Boon Leong <boon.leong.ong@intel.com>
Tested-by: Kurt Kanzenbach <kurt@linutronix.de>
Link: https://lore.kernel.org/r/20211013065941.2124858-1-boon.leong.ong@intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>