ethdev: format generic xstats per queue always
ethdev: format generic xstats per queue always

This patch refactors the generic queue stats to be exposed
by rte_ethdev_xstats_get().

Signed-off-by: Harry van Haaren <b9ad04ed670c22cfa7f5f9ab17e311ca85d11a76@intel.com>
Acked-by: Maryam Tahhan <4186b129a1450294ee3c67173e770842b7c6caba@intel.com>

john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk