doc: announce deprecation of macros in hash API
doc: announce deprecation of macros in hash API

Two of the macros in rte_hash.h are now deprecated, so this patch
adds notice that they will be removed in 2.2.

Signed-off-by: Pablo de Lara <28355d9cfe41bb8148aea0fb24f47aae8f4217a1@intel.com>
Acked-by: Bruce Richardson <66b9e8e8fbd5e9f41f91b0af050876182ce9d0e4@intel.com>

tsphillips/dpdk-fork,mixja/dpdk,mixja/dpdk,msune/dpdk,tsphillips/dpdk-fork,msune/dpdk,tsphillips/dpdk-fork,venkynv/dpdk-mirror,john-mcnamara-intel/dpdk,venkynv/dpdk-mirror,msune/dpdk,mixja/dpdk,msune/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,tsphillips/dpdk-fork,venkynv/dpdk-mirror,venkynv/dpdk-mirror,mixja/dpdk