pvh: access to hypercalls

pvh: access to hypercalls

Hypercalls where we now have unrestricted access:
* memory_op
* console_io
* vcpu_op
* mmuext_op

We also restrict PVH domain access to HVMOP_*_param to reading and
writing HVM_PARAM_CALLBACK_IRQ.

Most hvm_op functions require "is_hvm_domain()" and will default to
-EINVAL; exceptions are HVMOP_get_time and HVMOP_xentrace.

Finally, we restrict setting IOPL permissions for a PVH domain.

Signed-off-by: Mukesh Rathor <mukesh.rathor@oracle.com>
Signed-off-by: George Dunlap <george.dunlap@eu.citrix.com>
Acked-by: Tim Deegan <tim@xen.org>
Acked-by: Keir Fraser <keir@xen.org>
Acked-by: Eddie Dong <eddie.dong@intel.com>