Update DebugPlugin.scala
Update DebugPlugin.scala

Add readback of the hardware breakpoint values.
A new parameter is added to the plugin to switch readback on and off.
SpinalHDL/VexRiscv,SpinalHDL/VexRiscv,SpinalHDL/VexRiscv,SpinalHDL/VexRiscv,SpinalHDL/VexRiscv