KVM: x86: Suppress code #DBs on Intel if MOV/POP SS blocking is active

KVM: x86: Suppress code #DBs on Intel if MOV/POP SS blocking is active

Suppress code breakpoints if MOV/POP SS blocking is active and the guest
CPU is Intel, i.e. if the guest thinks it's running on an Intel CPU.
Intel CPUs inhibit code #DBs when MOV/POP SS blocking is active, whereas
AMD (and its descendents) do not.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20220830231614.3580124-6-seanjc@google.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>