compress/qat: enable compression on GEN3

compress/qat: enable compression on GEN3

This patch enables the compression on QAT GEN3 (on hardware
versions that support it) and changes the error message shown
on older hardware versions that don't support the compression.

It also fixes the crash that happened on IM buffer allocation
failure (not enough memory) during the PMD cleaning phase.

Fixes: a124830a6f00 ("compress/qat: enable dynamic huffman encoding")
Fixes: 352332744c3a ("compress/qat: add dynamic SGL allocation")
Cc: stable@dpdk.org
Signed-off-by: Adam Dybkowski <adamx.dybkowski@intel.com>
Acked-by: Fan Zhang <roy.fan.zhang@intel.com>