KVM: PPC: booke: save/restore VRSAVE (a.k.a. USPRG0)

Linux doesn't use USPRG0 (now renamed VRSAVE in the architecture, even
when Altivec isn't involved), but a guest might.

Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
index 890897c..a168043 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -223,6 +223,7 @@
 	ulong hflags;
 	ulong guest_owned_ext;
 #endif
+	u32 vrsave; /* also USPRG0 */
 	u32 mmucr;
 	ulong sprg4;
 	ulong sprg5;