ClockSpeed not defined in /proc/cpuinfo for AArch64, so return 0.
ClockSpeed not defined in /proc/cpuinfo for AArch64, so return 0.

Signed-off-by: Yazen Ghannam <90fbc5f72d145c37c06c9ccf437a088384a94d6d@linaro.org>

pwittrock/cadvisor,ncdc/cadvisor,IFTTT/cadvisor,timstclair/cadvisor,jhjeong-kr/cadvisor,ncdc/cadvisor,pwittrock/cadvisor,guoshimin/cadvisor,shilpamayanna/cadvisor,IFTTT/cadvisor,feiskyer/cadvisor,afein/cadvisor,f0/cadvisor,derekwaynecarr/cadvisor,f0/cadvisor,feiskyer/cadvisor,erSitzt/cadvisor,f0/cadvisor,ncdc/cadvisor,f0/cadvisor,ncdc/cadvisor,datawisesystems/cadvisor,carmark/cadvisor,derekwaynecarr/cadvisor,normanjoyner/cadvisor,dchen1107/cadvisor,BrickXu/cadvisor,ainsleyc/cadvisor,erSitzt/cadvisor,BrickXu/cadvisor,afein/cadvisor,dchen1107/cadvisor,erSitzt/cadvisor,dchen1107/cadvisor,vishh/cadvisor,ainsleyc/cadvisor,derekwaynecarr/cadvisor,dchen1107/cadvisor,erSitzt/cadvisor,ainsleyc/cadvisor,datawisesystems/cadvisor,dchen1107/cadvisor,vishh/cadvisor,f0/cadvisor,guoshimin/cadvisor,derekwaynecarr/cadvisor,timstclair/cadvisor,IFTTT/cadvisor,IFTTT/cadvisor,BrickXu/cadvisor,pwittrock/cadvisor,jhjeong-kr/cadvisor,normanjoyner/cadvisor,jhjeong-kr/cadvisor,ncdc/cadvisor,jhjeong-kr/cadvisor,jhjeong-kr/cadvisor,ainsleyc/cadvisor,shilpamayanna/cadvisor,erSitzt/cadvisor,BrickXu/cadvisor,IFTTT/cadvisor,linux-on-ibm-z/cadvisor,carmark/cadvisor,BrickXu/cadvisor,vishh/cadvisor,linux-on-ibm-z/cadvisor,guoshimin/cadvisor,linux-on-ibm-z/cadvisor,timstclair/cadvisor,feiskyer/cadvisor,derekwaynecarr/cadvisor