kvm: svm: de-allocate svm_cpu_data for all cpus in svm_cpu_uninit()

The cpu arg for svm_cpu_uninit() was previously ignored resulting in the
per cpu structure svm_cpu_data not being de-allocated for all cpus.

Signed-off-by: Jacob Xu <jacobhxu@google.com>
Message-Id: <20201203205939.1783969-1-jacobhxu@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>