hash: support read/write concurrency

hash: support read/write concurrency

The existing implementation of librte_hash does not support read-write
concurrency. This commit implements read-write safety using rte_rwlock
and rte_rwlock TM version if hardware transactional memory is available.

Both multi-writer and read-write concurrency is protected by rte_rwlock
now. The x86 specific header file is removed since the x86 specific RTM
function is not called directly by rte hash now.

Signed-off-by: Yipeng Wang <yipeng1.wang@intel.com>
Acked-by: Pablo de Lara <pablo.de.lara.guarch@intel.com>