vmm: cpu: Add the CpuManager onto the IO bus

This allows the kernel (via ACPI based controls) to query and control
the CPU state.

Signed-off-by: Rob Bradford <robert.bradford@intel.com>

vmm/src/vm.rs

@@ -428,7 +428,8 @@ impl Vm {
             fd,
             cpuid,
             reset_evt,
-        );
+        )
+        .map_err(Error::CpuManager)?;
 
         Ok(Vm {
             kernel,