fixing two bugs which result in crashes on a 24-core a64fx (related to issue #599)

[jdomke]

bug 1: numCachesPerSocket is 0 and numberOfDomains is therefore calculated incorrectly resulting in writes to not allocated mem

bug 2: 24-core version of a64fx is essentiually a 48 core with some cores being disabled, but the core IDs are not numbered consecutively by the kernel resulting in segfaults in likwid