net/thunderx: cleanup

net/thunderx: cleanup

Refactored features:
 - enable nicvf_qset_rbdr_precharge to handle secondary queue sets
 - rte_free already handles NULL pointer
 - check mempool flags to predict being contiguous in memory
 - prohibit to use mempool with multiple memory chunks
 - simplify local construct of accessing nb_rx_queues
 - enable NICVF_CAP_CQE_RX2 on CN88XX PASS2.0 hardware.
 - remove redundant check for RSS size in nicvf_eth_dev_init

Signed-off-by: Maciej Czekaj <maciej.czekaj@caviumnetworks.com>
Signed-off-by: Kamil Rytarowski <kamil.rytarowski@caviumnetworks.com>
Signed-off-by: Zyta Szpak <zyta.szpak@semihalf.com>
Signed-off-by: Slawomir Rosek <slawomir.rosek@semihalf.com>
Signed-off-by: Radoslaw Biernacki <rad@semihalf.com>
Signed-off-by: Jerin Jacob <jerin.jacob@caviumnetworks.com>