net: am65-cpsw: cpsw_mdio: Switch to proper DM_MDIO framework

Add a new Kconfig symbol MDIO_TI_CPSW for the CPSW MDIO
driver and build it with proper DM support if enabled.

If MDIO_TI_CPSW is not enabled then we continue to
behave like before.

Clean up MDIO custom handling in am65-cpsw and use
dm_eth_phy_connect() to get the PHY.

Signed-off-by: Roger Quadros <rogerq@kernel.org>
Tested-by: Ravi Gunasekaran <r-gunasekaran@ti.com>
diff --git a/drivers/net/ti/Kconfig b/drivers/net/ti/Kconfig
index c75f4186..72eccc9 100644
--- a/drivers/net/ti/Kconfig
+++ b/drivers/net/ti/Kconfig
@@ -45,7 +45,15 @@
 	imply MISC_INIT_R
 	imply MISC
 	imply SYSCON
+	imply MDIO_TI_CPSW
 	select PHYLIB
 	help
 	  This driver supports TI K3 MCU CPSW Nuss Ethernet controller
 	  in Texas Instruments K3 AM65x SoCs.
+
+config MDIO_TI_CPSW
+	bool "TI CPSW MDIO interface support"
+	depends on DM_MDIO
+	help
+	  This driver supports the TI CPSW MDIO interface found in various
+	  TI SoCs.