KVM: arm64: Expose KVM_ARM_VCPU_REC to user space

Increment KVM_VCPU_MAX_FEATURES to expose the new capability to user
space.

Signed-off-by: Steven Price <steven.price@arm.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
---
Changes since v8:
 * Since NV is now merged and enabled, this no longer conflicts with it.