[clocks] Update dealiaser based on feedback

generators/chipyard/src/main/scala/clocking/ClockGroupDealiaser.scala

@@ -9,7 +9,7 @@ import freechips.rocketchip.prci._
 /**
   * Somewhat hacky. Since not all clocks in a clock group specify a taken frequency
   * current, this LazyModule attempts to dealias them, by finding a specified
-  * clock whose name has the longest matching prefix.
+  * clock with a matching name.
   *
   * Perhaps another, simpler solution would be to pass a default.
   *
@@ -30,17 +30,16 @@ class ClockGroupDealiaser(name: String)(implicit p: Parameters) extends LazyModu
   val node = ClockGroupDealiaserNode()
 
   lazy val module = new LazyRawModuleImp(this) {
-    require(node.out.size == 1, "Must use a ClockGroupAggregator")
+    require(node.out.size == 1 && node.in.size == 1,
+      "ClockGroupDealiaser requires a single ClockGroup, please use a ClockGroupAggregator")
     val (outClocks, e @ ClockGroupEdgeParameters(_, outSinkParams,  _, _)) = node.out.head
     val (inClocks, ClockGroupEdgeParameters(_, inSinkParams,  _, _)) = node.in.head
     val inMap = inClocks.member.data.zip(inSinkParams.members).map({ case (b, p) => p.name -> b}).toMap
 
     for (((outBName, outB), outName) <- outClocks.member.elements.zip(outSinkParams.members.map(_.name))) {
       val inClock = inMap.getOrElse(outName, throw new Exception("""
-          | No clock in input group with name: Option matching ${outName}. At least one clock
+          | No clock in input group with name option matching ${outName}. At least one clock
           | with the same must specify a frequency in its take parameter.""".stripMargin))
-      // This will be removed.
-      dontTouch(outB)
       outB := inClock
     }
   }