netdev-dpdk: Remove Rx checksum reconfigure.

netdev-dpdk: Remove Rx checksum reconfigure.

Rx checksum offload is enabled by default on DPDK physical NICs
where available, with reconfiguration through
options:rx-checksum-offload. However, changing rx-checksum-offload
did not result in a reconfiguration of the NIC and wrong status is
reported for it.

As there seems to be diminishing reasons why a user would want
to disable Rx checksum offload, just remove the broken reconfiguration
option.

Fixes: 1a2bb11817a4 ("netdev-dpdk: Enable Rx checksum offloading feature on DPDK physical ports.")
Reported-by: Kevin Traynor <ktraynor@redhat.com>
Suggested-by: Sugesh Chandran <sugesh.chandran@intel.com>
Acked-by: Darrell Ball <dlu998@gmail.com>
Tested-by: Sugesh Chandran <sugesh.chandran@intel.com>
Signed-off-by: Kevin Traynor <ktraynor@redhat.com>
Signed-off-by: Ben Pfaff <blp@ovn.org>