net/ena: use correct field for Rx offload features
net/ena: use correct field for Rx offload features

Previously the capability bitmap for Rx offloads was mistakenly taken
from Tx capability bitmap field. This patch fixes the problem.

Signed-off-by: Jakub Palider <1a2f18c7887fc8d384193bb926e616097dea5b69@semihalf.com>

john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk