Implement generators for ScalaCheck for AXI configurations

src/test/scala/axi/generators.scala

+package chisel.axi.axi4
+import  chisel.axi.generators._
+import  org.scalacheck.{Arbitrary, Gen}
+
+package object generators {
+  object Axi4 {
+    val configurationGen: Gen[chisel.axi.Axi4.Configuration] = for {
+      addrWidth   <- addrWidthGen
+      dataWidth   <- dataWidthGen
+      userWidth   <- userWidthGen
+      idWidth     <- idWidthGen
+      regionWidth <- regionWidthGen
+      hasQoS      <- Arbitrary.arbBool.arbitrary
+    } yield chisel.axi.Axi4.Configuration(addrWidth, dataWidth, idWidth, userWidth, regionWidth, hasQoS)
+  }
+
+  object Axi4Lite {
+    val dataWidthGen: Gen[chisel.axi.Axi4Lite.DataWidth] = Gen.oneOf(
+      chisel.axi.Axi4Lite.Width32,
+      chisel.axi.Axi4Lite.Width64
+    )
+
+    val configurationGen: Gen[chisel.axi.Axi4Lite.Configuration] = for {
+      addrWidth   <- addrWidthGen
+      dataWidth   <- dataWidthGen
+      userWidth   <- userWidthGen
+      regionWidth <- regionWidthGen
+    } yield chisel.axi.Axi4Lite.Configuration(addrWidth, dataWidth, userWidth, regionWidth)
+  }
+}

src/test/scala/axi4lite/generators.scala

+package chisel.axiutils.axi4lite
+import  chisel.axiutils.generators._
+
+package object generators {
+}

src/test/scala/generators.scala

+package chisel.axi
+import  chisel.miscutils.generators._
+import  org.scalacheck._
+
+package object generators {
+  val addrWidthGen: Gen[AddrWidth]     = genLimited(1, 64) map (AddrWidth(_))
+  val dataWidthGen: Gen[DataWidth]     = genLimited(1, 4096) map (DataWidth(_))
+  val userWidthGen: Gen[UserWidth]     = Gen.frequency(
+    90 -> UserWidth(0),
+    10 -> (genLimited(1, 15) map (UserWidth(_)))
+  )
+  val idWidthGen: Gen[IdWidth]         = genLimited(0, 15) map (IdWidth(_))
+  val regionWidthGen: Gen[RegionWidth] = genLimited(0, 4) map (RegionWidth(_))
+}