hammerhead: Remove the maxcpus arg

 * This is fixed in the kernel now.

Change-Id: Icfde43adfb9db4402232e7ef71e3e197dc193d43
hammerhead: disable cpu-boost

* The CPU-boost driver doesn't seem to behave correctly quite yet,
  disable it until it can be fixed.

Change-Id: Idec7151b6324d182828c748ff781de92d320e4f9