KVM: docs: mmu: KVM support exposing SLAT to guests

Fix outdated statement that KVM is not able to expose SLAT
(Second-Layer-Address-Translation) to guests.
This was implemented a long time ago...
Signed-off-by: Liran Alon <liran.alon@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Documentation/virtual/kvm/mmu.txt

@@ -49,8 +49,8 @@ The mmu supports first-generation mmu hardware, which allows an atomic switch
 of the current paging mode and cr3 during guest entry, as well as
 two-dimensional paging (AMD's NPT and Intel's EPT).  The emulated hardware
 it exposes is the traditional 2/3/4 level x86 mmu, with support for global
-pages, pae, pse, pse36, cr0.wp, and 1GB pages.  Work is in progress to support
-exposing NPT capable hardware on NPT capable hosts.
+pages, pae, pse, pse36, cr0.wp, and 1GB pages. Emulated hardware also
+able to expose NPT capable hardware on NPT capable hosts.
 
 Translation
 ===========