Kconfiglib: Warn for unquoted string defaults

Unquoted string defaults work through a quirk of Kconfig (undefined
symbols get their name as their string value), but look confusing. It's
done inconsistently now too.

Suggested by Kumar Gala.

Signed-off-by: Ulf Magnusson <Ulf.Magnusson@nordicsemi.no>
1 file changed