setup: Don't use the automatic "find_namespace:" discovery

This automatic discovery doesn't fit to the flat layout of my package
(without the "src" directory).

Instead, let's specify the "packages" explicitly in setup.cfg.

setup.cfg

@@ -17,12 +17,14 @@ classifiers =
 
 [options]
 setup_requires = setuptools
-packages = find_namespace:
+packages =
+	kconfig_hardened_check
+	kconfig_hardened_check.config_files
+	kconfig_hardened_check.config_files.defconfigs
+	kconfig_hardened_check.config_files.distros
+	kconfig_hardened_check.config_files.kspp-recommendations
 include_package_data = true
 
-[options.packages.find]
-where = kconfig_hardened_check
-
 [options.entry_points]
 console_scripts =
 	kconfig-hardened-check = kconfig_hardened_check:main