[dts] [PATCH V2] tests/checksum_offload & tests/rxtx_offload: adapt DPDK bad UDP checksum's change

[Tu, Lijuan]

> v1: modify dts for adapt DPDK bad UDP checksum change from
> PKT_RX_L4_CKSUM_BAD
>      to PKT_RX_L4_CKSUM_UNKNOWN
> 
> v2: add DPDK change UDP checksum version: 21.02 rc3
> 
> Signed-off-by: Zhou Jun <junx.w.zhou at intel.com>

Applied with commit message changed.