Add "prot_virt" command line option which controls if the kernel
protected VMs support is enabled at early boot time. This has to be
done early, because it needs large amounts of memory and will disable
some features like STP time sync for the lpar.

Extend ultravisor info definitions and expose it via uv_info struct
filled in during startup.
Signed-off-by: NVasily Gorbik <gor@linux.ibm.com>
Reviewed-by: NThomas Huth <thuth@redhat.com>
Acked-by: NDavid Hildenbrand <david@redhat.com>
Reviewed-by: NCornelia Huck <cohuck@redhat.com>
Acked-by: NChristian Borntraeger <borntraeger@de.ibm.com>
[borntraeger@de.ibm.com: patch merging, splitting, fixing]
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>