drivers: ethernet: phy: Add Intel IGC PHY driver

Intel IGC(aka Foxville) is a fully integrated MAC and PHY. This commit
adds support for the Intel IGC PHY driver with the following features:

- Support 10/100/1000 BASE-T.
- Auto Negotiation for 10/100/1000 Mbps speeds.
- Integration with the MDIO interface for PHY register access.
- PHY link interrupt service handler.
- Device tree support for PHY configuration and initialization.

It uses the MDIO interface to communicate with the PHY and supports
modular configuration via the device tree.

Signed-off-by: Vijayakannan Ayyathurai <vijayakannan.ayyathurai@intel.com>
Signed-off-by: Ling Pei Lee <pei.lee.ling@intel.com>

Author: Vijayakannan

drivers/ethernet/phy/CMakeLists.txt

@@ -5,6 +5,7 @@ zephyr_library_sources_ifdef(CONFIG_PHY_GENERIC_MII	phy_mii.c)
 # zephyr-keep-sorted-start
 zephyr_library_sources_ifdef(CONFIG_PHY_ADIN2111	phy_adin2111.c)
 zephyr_library_sources_ifdef(CONFIG_PHY_DM8806	phy_dm8806.c)
+zephyr_library_sources_ifdef(CONFIG_PHY_INTEL_IGC  phy_intel_igc.c)
 zephyr_library_sources_ifdef(CONFIG_PHY_MICROCHIP_KSZ8081	phy_microchip_ksz8081.c)
 zephyr_library_sources_ifdef(CONFIG_PHY_MICROCHIP_T1S phy_microchip_t1s.c)
 zephyr_library_sources_ifdef(CONFIG_PHY_MICROCHIP_VSC8541 phy_microchip_vsc8541.c)

drivers/ethernet/phy/Kconfig

@@ -122,4 +122,12 @@ config PHY_VERIFY_DEVICE_IDENTIFICATION
 	  Verify the organizationally unique identifier that is reported
 	  by the phy chip.
 
+config PHY_INTEL_IGC
+	bool "Intel IGC PHY driver"
+	default y
+	depends on DT_HAS_INTEL_IGC_PHY_ENABLED
+	depends on MDIO_INTEL_IGC
+	help
+	  Enable Intel IGC PHY driver.
+
 endif # "Ethernet PHY Drivers"