We were using the .cfg suffix for both the build-time config fragments and the
runtime configuration file. During do_configure(), all files in SRC_URI ending
in .cfg were being merged together to create the final build configuration,
including said runtime file, which has a completely different syntax. In most
cases, the contents of this file were being ignored, but when tweaking
swupdate's configuration and re-building the package, sometimes strange errors
would prevent the build from finishing.
Change the runtime file's suffix entirely to separate it from the config
fragments and prevent it from being treated as such, and reflect the name
change in the defconfig and the recovery script.
Signed-off-by: Gabriel Valcazar <gabriel.valcazar@digi.com>