separate PWM and basic example into separate packages

src/main/scala/example/Top.scala

@@ -0,0 +1,23 @@
+package example
+
+import chisel3._
+import cde.Parameters
+import testchipip._
+import rocketchip._
+
+class ExampleTop(q: Parameters) extends BaseTop(q)
+    with PeripheryBootROM with PeripheryCoreplexLocalInterrupter
+    with PeripherySerial with PeripheryMasterMem {
+  override lazy val module = Module(
+    new ExampleTopModule(p, this, new ExampleTopBundle(p)))
+}
+
+class ExampleTopBundle(p: Parameters) extends BaseTopBundle(p)
+  with PeripheryBootROMBundle with PeripheryCoreplexLocalInterrupterBundle
+  with PeripheryMasterMemBundle with PeripherySerialBundle
+
+class ExampleTopModule[+L <: ExampleTop, +B <: ExampleTopBundle](p: Parameters, l: L, b: => B)
+  extends BaseTopModule(p, l, b)
+  with PeripheryBootROMModule with PeripheryCoreplexLocalInterrupterModule
+  with PeripheryMasterMemModule with PeripherySerialModule
+  with HardwiredResetVector with DirectConnection with NoDebug