Convert CONFIG_PHYLIB et al to Kconfig

This converts the following to Kconfig:
   CONFIG_PHYLIB
   CONFIG_BITBANGMII
   CONFIG_MV88E6352_SWITCH
   CONFIG_MV88E61XX_SWITCH
   CONFIG_PHYLIB_10G
   CONFIG_PHY_AQUANTIA
   CONFIG_PHY_ATHEROS
   CONFIG_PHY_BROADCOM
   CONFIG_PHY_CORTINA
   CONFIG_PHY_DAVICOM
   CONFIG_PHY_ET1011C
   CONFIG_PHY_LXT
   CONFIG_PHY_MARVELL
   CONFIG_PHY_MICREL
   CONFIG_PHY_NATSEMI
   CONFIG_PHY_REALTEK
   CONFIG_RTL8211X_PHY_FORCE_MASTER
   CONFIG_PHY_SMSC
   CONFIG_PHY_TERANETICS
   CONFIG_PHY_TI
   CONFIG_PHY_VITESSE
   CONFIG_PHY_XILINX

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/stm32f746-disco_defconfig b/configs/stm32f746-disco_defconfig
index c9e2256..cdfa8bb 100644
--- a/configs/stm32f746-disco_defconfig
+++ b/configs/stm32f746-disco_defconfig
@@ -46,6 +46,7 @@
 CONFIG_DM_SPI_FLASH=y
 CONFIG_SPI_FLASH_MACRONIX=y
 CONFIG_SPI_FLASH_STMICRO=y
+CONFIG_PHY_SMSC=y
 CONFIG_DM_ETH=y
 CONFIG_ETH_DESIGNWARE=y
 CONFIG_MII=y