KVM: x86: nSVM: don't copy pause related settings

According to the SDM, the CPU never modifies these settings.
It loads them on VM entry and updates an internal copy instead.

Also don't load them from the vmcb12 as we don't expose these
features to the nested guest yet.

Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20210914154825.104886-5-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>