KVM: arm/arm64: Enable KVM_CAP_NR_MEMSLOTS on arm/arm64

Return KVM_USER_MEM_SLOTS for userspace capability query on
NR_MEMSLOTS.

Reviewed-by: Christoffer Dall <cdall@linaro.org>
Signed-off-by: Linu Cherian <linu.cherian@cavium.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

arch/arm/kvm/arm.c

@@ -221,6 +221,9 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
 	case KVM_CAP_MAX_VCPUS:
 		r = KVM_MAX_VCPUS;
 		break;
+	case KVM_CAP_NR_MEMSLOTS:
+		r = KVM_USER_MEM_SLOTS;
+		break;
 	case KVM_CAP_MSI_DEVID:
 		if (!kvm)
 			r = -EINVAL;