KVM: selftests: Ignore recently added Xen tests' build output

Add the new Xen test binaries to KVM selftest's .gitnore.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210210182609.435200-2-seanjc@google.com>
Reviewed-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

tools/testing/selftests/kvm/.gitignore

@@ -26,6 +26,8 @@
 /x86_64/vmx_set_nested_state_test
 /x86_64/vmx_tsc_adjust_test
 /x86_64/xapic_ipi_test
+/x86_64/xen_shinfo_test
+/x86_64/xen_vmcall_test
 /x86_64/xss_msr_test
 /x86_64/vmx_pmu_msrs_test
 /demand_paging_test