scripts/liberty: Adding a `--debug` option.

Signed-off-by: Tim 'mithro' Ansell <me@mith.ro>
diff --git a/scripts/python-skywater-pdk/skywater_pdk/liberty.py b/scripts/python-skywater-pdk/skywater_pdk/liberty.py
index f0686f9..b7d61b1 100755
--- a/scripts/python-skywater-pdk/skywater_pdk/liberty.py
+++ b/scripts/python-skywater-pdk/skywater_pdk/liberty.py
@@ -843,8 +843,16 @@
             help="Include power leakage in file output.",
             action='store_true',
             default=False)
+    parser.add_argument(
+            "--debug",
+            help="Include verbose debug output on the console.",
+            action='store_true',
+            default=False)
 
     args = parser.parse_args()
+    if args.debug:
+        global debug
+        debug = True
 
     libdir = args.library_path[0]