scripts: Add Kconfiglib v14.1.0 under scripts directory

We adopt Kconfiglib v14.1.0 sources under scripts directory so that
top-level OpenSBI makefile can directly use Kconfiglib scripts without
expecting users to install a particular version of Kconfiglib on their
build system.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Tested-by: Andrew Jones <ajones@ventanamicro.com>
Acked-by: Atish Patra <atishp@rivosinc.com>
Tested-by: Atish Patra <atishp@rivosinc.com>

scripts/Kconfiglib/savedefconfig.py

@@ -0,0 +1,49 @@
+#!/usr/bin/env python3
+
+# Copyright (c) 2019, Ulf Magnusson
+# SPDX-License-Identifier: ISC
+
+"""
+Saves a minimal configuration file that only lists symbols that differ in value
+from their defaults. Loading such a configuration file is equivalent to loading
+the "full" configuration file.
+
+Minimal configuration files are handy to start from when editing configuration
+files by hand.
+
+The default input configuration file is '.config'. A different input filename
+can be passed in the KCONFIG_CONFIG environment variable.
+
+Note: Minimal configurations can also be generated from within the menuconfig
+interface.
+"""
+import argparse
+
+import kconfiglib
+
+
+def main():
+    parser = argparse.ArgumentParser(
+        formatter_class=argparse.RawDescriptionHelpFormatter,
+        description=__doc__)
+
+    parser.add_argument(
+        "--kconfig",
+        default="Kconfig",
+        help="Top-level Kconfig file (default: Kconfig)")
+
+    parser.add_argument(
+        "--out",
+        metavar="MINIMAL_CONFIGURATION",
+        default="defconfig",
+        help="Output filename for minimal configuration (default: defconfig)")
+
+    args = parser.parse_args()
+
+    kconf = kconfiglib.Kconfig(args.kconfig, suppress_traceback=True)
+    print(kconf.load_config())
+    print(kconf.write_min_config(args.out))
+
+
+if __name__ == "__main__":
+    main()