Kernel: Enable VMWareBackdoor immediately at boot

Rather than waiting until we get the first mouse packet, enable the
absolute mode immediately. This avoids having to click first to be
able to move the mouse.

Kernel/init.cpp

@@ -265,6 +265,7 @@ void init_stage2()
     new RandomDevice;
     PTYMultiplexer::initialize();
     new SB16;
+    VMWareBackdoor::the(); // don't wait until first mouse packet
 
     bool force_pio = kernel_command_line().contains("force_pio");