Add local interrupts to core (but not yet to coreplex)

src/main/scala/tile/Core.scala

@@ -23,6 +23,7 @@ trait CoreParams {
   val decodeWidth: Int
   val retireWidth: Int
   val instBits: Int
+  val nLocalInterrupts: Int
 }
 
 trait HasCoreParameters extends HasTileParameters {

src/main/scala/tile/Interrupts.scala

@@ -7,6 +7,7 @@ import config.Parameters
 import util._
 
 class TileInterrupts(implicit p: Parameters) extends CoreBundle()(p) {
+  val lip = Vec(coreParams.nLocalInterrupts, Bool())
   val debug = Bool()
   val mtip = Bool()
   val msip = Bool()