pvh: disable unneeded features of HVM containers

pvh: disable unneeded features of HVM containers

Things kept:
* cacheattr_region lists
* irq-related structures
* paging
* tm_list
* hvm params
* hvm_domaim.io_handler (for handling PV io)

Things disabled for now:
* compat xlation

Things disabled:
* Emulated timers and clock sources
* IO/MMIO ioreq pages, event channels
* msix tables
* hvm_funcs
* nested HVM
* Fast-path for emulated lapic accesses

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