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/xpedite520x_defconfig b/configs/xpedite520x_defconfig
index 183108c..b006dea 100644
--- a/configs/xpedite520x_defconfig
+++ b/configs/xpedite520x_defconfig
@@ -30,7 +30,8 @@
 CONFIG_CMD_PCA953X=y
 # CONFIG_MMC is not set
 CONFIG_MTD_NOR_FLASH=y
-CONFIG_PHYLIB=y
+CONFIG_NETDEVICES=y
+CONFIG_TSEC_ENET=y
 CONFIG_SYS_NS16550=y
 CONFIG_PANIC_HANG=y
 CONFIG_OF_LIBFDT=y