net: phy: Iterate over both registered PHYs and struct phy_driver linker list

Introduce U_BOOT_PHY_DRIVER() macro which is used to add struct phy_driver
into a new linker list section containing all compiled in struct phy_driver
drivers. This is so far empty until PHY drivers are converted over to this
macro.

Iterate over both drivers registered using soon to be legacy phy_register()
as well as drivers in the new linker list when looking up a suitable PHY
driver. This way, PHY drivers can be converted over to the new macro one
driver at a time.

The relocation of callbacks for linker list based drivers now happens in
phy_init() call as the drivers are available at that point in time, and
phy_register() is not called for those drivers.

Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
Acked-by: Michal Simek <michal.simek@amd.com>
Tested-by: Michal Simek <michal.simek@amd.com> #microblaze (MANUAL_RELOC)

include/phy.h

@@ -345,6 +345,13 @@ int phy_fixed_init(void);
 int phy_ncsi_init(void);
 int phy_xilinx_gmii2rgmii_init(void);
 
+/**
+ * U_BOOT_PHY_DRIVER() - Declare a new U-Boot driver
+ * @__name: name of the driver
+ */
+#define U_BOOT_PHY_DRIVER(__name)					\
+	ll_entry_declare(struct phy_driver, __name, phy_driver)
+
 int board_phy_config(struct phy_device *phydev);
 int get_phy_id(struct mii_dev *bus, int addr, int devad, u32 *phy_id);