treewide: Migrate CONFIG_TSEC_ENET to Kconfig

Migrate the CONFIG_TSEC_ENET option to Kconfig.

Signed-off-by: Mario Six <mario.six@gdsys.cc>
diff --git a/configs/MPC837XEMDS_defconfig b/configs/MPC837XEMDS_defconfig
index def268d..e6878ba 100644
--- a/configs/MPC837XEMDS_defconfig
+++ b/configs/MPC837XEMDS_defconfig
@@ -21,7 +21,8 @@
 CONFIG_BOOTP_GATEWAY=y
 CONFIG_BOOTP_HOSTNAME=y
 CONFIG_MTD_NOR_FLASH=y
-CONFIG_PHYLIB=y
+CONFIG_NETDEVICES=y
+CONFIG_TSEC_ENET=y
 # CONFIG_PCI is not set
 CONFIG_SYS_NS16550=y
 CONFIG_OF_LIBFDT=y