Add vcpu_stat related items to display, include:
EXThvc: hvc kvm exit
EXTWFE: wfe kvm exit
EXTwfi: wfi kvm exit
EXTmmioU: mmio User kvm exit
EXTmmioK: mmio Kernel kvm exit
EXTfp: FP ASIMD kvm exit
EXTirq: IRQ kvm exit
EXTsys64: SYS64 kvm  exit
EXTmabt: mem abort kvm exit
EXTsum: times of all kvm exit
Signed-off-by: NJiajun Chen <1250062498@qq.com>