Kernel/USB: Start fleshing out a basic UHCI controller driver :^)

Let's see if we can talk to some USB devices. We will now detect
a UHCI controller if present on the PCI bus.

Kernel/init.cpp

@@ -46,6 +46,7 @@
 #include <Kernel/Devices/RandomDevice.h>
 #include <Kernel/Devices/SB16.h>
 #include <Kernel/Devices/SerialDevice.h>
+#include <Kernel/Devices/UHCIController.h>
 #include <Kernel/Devices/VMWareBackdoor.h>
 #include <Kernel/Devices/ZeroDevice.h>
 #include <Kernel/FileSystem/Ext2FileSystem.h>
@@ -246,6 +247,8 @@ void init_stage2()
         }
     }
 
+    UHCIController::detect();
+
     E1000NetworkAdapter::detect();
     RTL8139NetworkAdapter::detect();