introduce XENMEM_reserved_device_memory_map

introduce XENMEM_reserved_device_memory_map

This is a prerequisite for punching holes into HVM and PVH guests' P2M
to allow passing through devices that are associated with (on VT-d)
RMRRs.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Tiejun Chen <tiejun.chen@intel.com>
Acked-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
---
v12a: Move interface structure union member to the end, while moving
     the whole public header block into a __XEN__ / __XEN_TOOLS__
     conditional block.
v12: Restore changes as much as possible to my original version, fixing
     a few issues that got introduced after handing it over. Unionize
     new public memop interface structure to allow for non-PCI to be
     supported later on. Check flags to have all currently undefined
     flags clear. Refine adjustments to xen/pci.h.