net/mlx4: fix CRC stripping capability report

net/mlx4: fix CRC stripping capability report

There are two capabilities related to CRC stripping:
1. mlx4 HW capability to perform CRC stripping on a received packet.
This capability is built in mlx4 HW. It should be returned by the API
call mlx4_get_rx_queue_offloads().
2. mlx4 driver capability to enable/disable HW CRC stripping. This
capability is dependent on the driver version.

Before this commit the second capability was falsely returned by
the mentioned API. This commit fixes it by returning the first
capability.
mlx4 HW performs CRC stripping by default and this capability is
always reported as "true".

The ability to enable/disable CRC stripping is supported since this
commit and requires OFED version 4.3-1.5.0.0 or rdma-core version v18.
CRC stripping will be done by default regardless of its configuration
when working with OFED or rdma-core versions earlier than those
previously specified or before this commit.

Fixes: de1df14e6e6ec ("net/mlx4: support CRC strip toggling")
Cc: stable@dpdk.org
Signed-off-by: Ophir Munk <ophirmu@mellanox.com>