pvh prep: code motion

pvh prep: code motion

There are many functions where PVH requires some code in common with
HVM.  Rearrange some of these functions so that the code is together.

In general, the HVM code that PVH also uses includes:
 - cacheattr functionality
 - paging
 - hvm_funcs
 - hvm_assert_evtchn_irq tasklet
 - tm_list
 - hvm_params

And code that PVH shares with PV but not with PVH:
 - updating the domain wallclock
 - setting v->is_initialized

There should be no end-to-end changes in behavior.

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>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Keir Fraser <keir@xen.org>
Acked-by: Eddie Dong <eddie.dong@intel.com>