[PATCH v2 2/2] eal: add Arm WFET in power management intrinsics

[Wathsala Wathawana Vithanage]

> 
> We are using this flag to allow application to choose between WFE and non-
> WFE code path.
> The non-WFE path performs slightly better.
> 

Is it correct if I assume that this flag is not used to indicate the availability 
of WFE instruction in any of your platforms?
If so, then its usage is to choose between WFE and non-WFE implementations
for performance reasons.