Use KConfig for /cfg filesystem size

Because clearfog and Epia have vastly differing flash sizes, we will
have to specify the desired size of the /cfg filesystem template that we
are making. Let's convert this to a "package" so that we have easy
access to the Kconfig tools -- even though it really isn't about any
"package" per se. On a flip side, this should allow for proper
parallelization of image building, yay!

Change-Id: Ic95a201ab7874711514bdc8b2e60b711db97ddc0
diff --git a/Config.in b/Config.in
index 3565239..4de0d4a 100644
--- a/Config.in
+++ b/Config.in
@@ -1,4 +1,4 @@
-source "$BR2_EXTERNAL_CZECHLIGHT_PATH/package/cla-sysrepo/Config.in"
+source "$BR2_EXTERNAL_CZECHLIGHT_PATH/package/Config.in"
 
 config CZECHLIGHT_NETCONF
 	bool "Complete NETCONF server and HW drivers"