net/ixgbe: fix multi-queue mode check in SRIOV mode

In SRIOV case, ETH_MQ_RX_VMDQ_DCB and ETH_MQ_RX_DCB should be considered as
the same meaning, due to the multi-queue mapping is the same SRIOV and VMDq
in ixgbe.

Fixes: 27b609cbd1c6 ("ethdev: move the multi-queue mode check to specific drivers")
Cc: stable@dpdk.org
Signed-off-by: Jingjing Wu <jingjing.wu@intel.com>