util: Add a "toEnergy" function to the convert module.

Change-Id: I7299af0e2a6ce9bd2272d6ccb898997336e95e51
Reviewed-on: https://gem5-review.googlesource.com/5623
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

src/python/m5/util/convert.py

@@ -242,3 +242,6 @@ def toVoltage(value):
 
 def toCurrent(value):
     return toMetricFloat(value, 'current', 'A')
+
+def toEnergy(value):
+    return toMetricFloat(value, 'energy', 'J')