[util] Fix lint in dvsim.py

Python (and flake8 in particular) doesn't like tabulation of
dictionaries. This was added in commit 2de350a (in PR #2994), but
apparently our CI didn't run for that commit so we didn't notice the
breakage :-(

Signed-off-by: Rupert Swarbrick <rswarbrick@lowrisc.org>
diff --git a/util/dvsim/dvsim.py b/util/dvsim/dvsim.py
index d060f11..a4acd90 100755
--- a/util/dvsim/dvsim.py
+++ b/util/dvsim/dvsim.py
@@ -146,11 +146,11 @@
     # the tool by reading the config file. At the moment, this forces a
     # simulation target (TODO?)
     factories = {
-        'ascentlint'  : LintCfg.LintCfg,
-        'veriblelint' : LintCfg.LintCfg,
-        'verilator'   : LintCfg.LintCfg,
-        'dc'          : SynCfg.SynCfg,
-        'jaspergold'  : FpvCfg.FpvCfg
+        'ascentlint': LintCfg.LintCfg,
+        'veriblelint': LintCfg.LintCfg,
+        'verilator': LintCfg.LintCfg,
+        'dc': SynCfg.SynCfg,
+        'jaspergold': FpvCfg.FpvCfg
     }
 
     factory = factories.get(args.tool, SimCfg.SimCfg)