KVM: SVM: Cleanup NMI singlestep

Push the NMI-related singlestep variable into vcpu_svm. It's dealing
with an AMD-specific deficit, nothing generic for x86.

Acked-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
 arch/x86/include/asm/kvm_host.h |    1 -
 arch/x86/kvm/svm.c              |   12 +++++++-----
 2 files changed, 7 insertions(+), 6 deletions(-)
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>