Irqmp - Add write protected zeroed register at 0x20.
Irqmp - Add write protected zeroed register at 0x20.

This is satisfying the rtems driver and producing less warnings

hoangt/core,socrocket/core,hlange/LogSoCR,hoangt/core,hlange/LogSoCR,hoangt/core,hlange/LogSoCR,hlange/LogSoCR,hlange/LogSoCR,hoangt/core,hlange/LogSoCR,hoangt/core,hlange/LogSoCR,hlange/LogSoCR,hoangt/core,hlange/LogSoCR,hlange/LogSoCR,socrocket/core,socrocket/core,socrocket/core,hlange/LogSoCR,socrocket/core,socrocket/core,hlange/LogSoCR,socrocket/core,hoangt/core,hoangt/core,hlange/LogSoCR,socrocket/core