3n-tsh timeout, testbed tags and ansible update

* disable AVF tests which don't work with x520
* increase VPPApiClient timeout to 14s, as x520 show hardware is slower
  on Taishan
* re-enable vhost and memif tests
* remove tx2 mrr daily tag list; no tx2 is used for perf testing
* remove taishan workaround
* add scipy arm prerequisites and scipy workaround
* rework inventories/lf_inventory/hosts; move cpu_microarchitecture to
host files

Change-Id: I5f10bd07b8146ac3b8be8c54fbb4d924a9373813
Signed-off-by: juraj.linkes <juraj.linkes@pantheon.tech>