tools/kvm_stat: update exit reasons for vmx/svm/aarch64/userspace

Update EXIT_REASONS from source, including VMX_EXIT_REASONS,
SVM_EXIT_REASONS, AARCH64_EXIT_REASONS, USERSPACE_EXIT_REASONS.

Signed-off-by: Rong Tao <rongtao@cestc.cn>
Message-Id: <tencent_00082C8BFA925A65E11570F417F1CD404505@qq.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>