clearfog: simplify config

It's brought in indirectly as a transitive dependency, and `make
savedefconfig` is happy to keep the config minimal.

Fixes: c690df2 netconf-cli: use libnetconf2-cpp
Change-Id: Ifd5d6703339df5e5b23f2f75aea881229085d35c
diff --git a/configs/czechlight_clearfog_defconfig b/configs/czechlight_clearfog_defconfig
index bf1abe4..152f0b6 100644
--- a/configs/czechlight_clearfog_defconfig
+++ b/configs/czechlight_clearfog_defconfig
@@ -51,7 +51,6 @@
 BR2_PACKAGE_UBOOT_TOOLS_KWBOOT=y
 BR2_PACKAGE_CA_CERTIFICATES=y
 BR2_PACKAGE_LIBGPIOD_TOOLS=y
-BR2_PACKAGE_LIBNETCONF2_CPP=y
 BR2_PACKAGE_NETOPEER2=y
 BR2_PACKAGE_NETOPEER2_CLI=y
 BR2_PACKAGE_ELFUTILS=y