dev,cpu,configs: Get rid of the IntrControl device.

This vestigial device provides a thin layer of indirection between
devices and the CPUs in a system. It's basically a collection of helper
functions, but since it's a SimObject it needs to be instantiated in
python and added to configurations.

Change-Id: I029d2314ae0bb890678e1e68dafcdab4bfe49beb
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/43347
Reviewed-by: Gabe Black <gabe.black@gmail.com>
Maintainer: Gabe Black <gabe.black@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>

configs/example/arm/devices.py

@@ -296,7 +296,6 @@ class BaseSimpleSystem(ArmSystem):
         if hasattr(self.realview.gic, 'cpu_addr'):
             self.gic_cpu_addr = self.realview.gic.cpu_addr
 
-        self.intrctrl = IntrControl()
         self.terminal = Terminal()
         self.vncserver = VncServer()