ixgbe: fix Rx with buffer address not word aligned

ixgbe: fix Rx with buffer address not word aligned

Niantic HW expects Header Buffer Address in the RXD to be word aligned.
So, if mbuf's buf_physaddr is not word aligned then
RX path will not work properly.
Right now, in ixgbe PMD we always setup Packet Buffer Address(PBA) and
Header Buffer Address (HBA) to the same value:
buf_physaddr + RTE_PKTMBUF_HEADROOM.
As ixgbe PMD doesn't support split header feature anyway,
the issue can be fixed just by always setting HBA in the RXD to zero.

Signed-off-by: Konstantin Ananyev <konstantin.ananyev@intel.com>