xsm: Dynamic update to device ocontexts

xsm: Dynamic update to device ocontexts

Added the ability to add and delete ocontexts dynamically on a running
system.  Two new commands have been added to the xsm hypercall, add
and delete ocontext.  Twelve new library functions have been
implemented that use the hypercall commands to label and unlabel
pirqs, PCI devices, I/O ports and memory.  The base policy has been
updated so dom0 has the ability to use the hypercall commands by
default.  Items added to the list will not be present next time the
system reloads.  They will need to be added to the static policy.

Signed-off-by : George Coker <gscoker@alpha.ncsc.mil>
Signed-off-by : Paul Nuzzi <pjnuzzi@tycho.ncsc.mil>