[dv] Add simulation result summary page

Here is the report that will be generated
https://reports.opentitan.org/hw/top_earlgrey/dv/summarys.html
Also fix xbar coverage error

Signed-off-by: Weicai Yang <weicai@google.com>
diff --git a/util/tlgen/generate.py b/util/tlgen/generate.py
index 6320783..3b39ab0 100644
--- a/util/tlgen/generate.py
+++ b/util/tlgen/generate.py
@@ -3,6 +3,7 @@
 # SPDX-License-Identifier: Apache-2.0
 
 import logging as log
+
 from mako import exceptions
 from mako.template import Template
 from pkg_resources import resource_filename
@@ -11,7 +12,6 @@
 from .xbar import Xbar
 
 
-
 def generate(xbar):  #xbar: Xbar -> str
     """generate uses elaborated model then creates top level Xbar module
     with prefix.