Expand scope of the Biba policy to include some of the new entry

Expand scope of the Biba policy to include some of the new entry
points available for enforcement:

  mac_biba_check_sysarch_ioperm() - Require Biba privilege to make
  use of privileged machine-dependent interfaces, protecting against
  bypass of the policy via various mechanisms.

  mac_biba_check_system_swapoff() - Require Biba privilege to disable
  swapping against a vnode target.

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories