net: phy: Bind ETH_PHY uclass driver to each new PHY

In case a new PHY is created and DM_ETH_PHY is enabled, bind a
generic PHY driver from ETH_PHY uclass to the PHY to have a
matching DM representation of that PHY.

Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
Reviewed-by: Ramon Fried <rfried.dev@gmail.com>