Scatter Rx is already supported by CXGBE PMD. So, add the missing
DEV_RX_OFFLOAD_SCATTER flag to the list of supported Rx offload
features.
Also, move the macros for supported list of offload features to
header file.
Fixes: 436125e64174 ("net/cxgbe: update to Rx/Tx offload API")
Cc: stable@dpdk.org
Reported-by: Martin Weiser <martin.weiser@allegro-packets.com>
Signed-off-by: Rahul Lakkireddy <rahul.lakkireddy@chelsio.com>