pseries: Remove unnecessary locking from PAPR hash table hcalls

In the paravirtualized environment provided by PAPR, there is a standard
locking scheme so that hypercalls updating the hash page table from
different guest threads don't corrupt the haah table state.  We implement
this HVLOCK bit in out page table hypercalls.  However, it is not necessary
in our case, since the hypercalls all run in the qemu environment under the
big qemu lock.

Therefore, this patch removes the locking code.  This has the additional
advantage of freeing up a hash PTE bit which will be useful for migration
support.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Alexander Graf <agraf@suse.de>
