kvm: decode the argument of KVM_SET_CPUID2 and KVM_GET_*_CPUID ioctl commands

kvm: decode the argument of KVM_SET_CPUID2 and KVM_GET_*_CPUID ioctl commands

* configure.ac (AC_CHECK_TYPES): Add struct kvm_cpuid2.
* xlat/kvm_cpuid_flags.in: New file.
* kvm.c [HAVE_STRUCT_KVM_CPUID2]: Include "xlat/kvm_cpuid_flags.h".
[HAVE_STRUCT_KVM_CPUID2] (print_kvm_cpuid_entry, kvm_ioctl_decode_cpuid2):
New functions.
(kvm_ioctl) [HAVE_STRUCT_KVM_CPUID2]: Use kvm_ioctl_decode_cpuid2.
* NEWS: Mention this improvement.

Signed-off-by: Pierre Marsais <pierre.marsais@lse.epita.fr>
Co-Authored-by: Dmitry V. Levin <ldv@altlinux.org>