[reggen] Minor fix to REGWEN error message

Relates to #5267

Signed-off-by: Tom Roberts <tomroberts@lowrisc.org>
diff --git a/util/reggen/validate.py b/util/reggen/validate.py
index 1b3edb7..7314cc7 100644
--- a/util/reggen/validate.py
+++ b/util/reggen/validate.py
@@ -753,7 +753,7 @@
             error += 1
             log.error(
                 "{x} used as regwen fails requirement to be "
-                "swaccess=W0C or swaccess=RO and hwaccess=HWO".format(x=x))
+                "swaccess=RW0C or swaccess=RO and hwaccess=HWO".format(x=x))
 
     return error