[PATCH net-next] net: phy: Cleanup struct mdio_driver_common

[kernel test robot]

Hi Yajun,

kernel test robot noticed the following build errors:

[auto build test ERROR on net-next/main]

url:    https://github.com/intel-lab-lkp/linux/commits/Yajun-Deng/net-phy-Cleanup-struct-mdio_driver_common/20231228-152806
base:   net-next/main
patch link:    https://lore.kernel.org/r/20231228072350.1294425-1-yajun.deng%40linux.dev
patch subject: [PATCH net-next] net: phy: Cleanup struct mdio_driver_common
config: s390-randconfig-002-20240103 (https://download.01.org/0day-ci/archive/20240104/202401040103.bTPaACUE-lkp@intel.com/config)
compiler: s390-linux-gcc (GCC) 13.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240104/202401040103.bTPaACUE-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp at intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202401040103.bTPaACUE-lkp@intel.com/

All errors (new ones prefixed by >>):

   s390-linux-ld: drivers/net/phy/mdio_bus.o: in function `mdio_bus_match':
>> mdio_bus.c:(.text+0xecc): undefined reference to `is_phy_driver'
   s390-linux-ld: drivers/net/phy/mdio_device.o: in function `mdio_device_bus_match':
>> mdio_device.c:(.text+0x934): undefined reference to `is_phy_driver'

-- 
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https://github.com/intel/lkp-tests/wiki