KVM: PPC: Book3S HV P9: Allow all P9 processors to enable nested HV

All radix guests go via the P9 path now, so there is no need to limit
nested HV to processors that support "mixed mode" MMU. Remove the
restriction.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210528090752.3542186-27-npiggin@gmail.com

arch/powerpc/kvm/book3s_hv.c

@@ -5451,7 +5451,7 @@ static int kvmhv_enable_nested(struct kvm *kvm)
 {
 	if (!nested)
 		return -EPERM;
-	if (!cpu_has_feature(CPU_FTR_ARCH_300) || no_mixing_hpt_and_radix)
+	if (!cpu_has_feature(CPU_FTR_ARCH_300))
 		return -ENODEV;
 
 	/* kvm == NULL means the caller is testing if the capability exists */