Setting up WRAP bit to indicate that this is the last TX BD in the
chain. On ZynqMP this problem was workaround by enabling TX_EN bit for
every packet send by "zynqmp: gem: GEM changes to make it work on ep108
RTL 3.1" (sha1: 01cf5de125122a10c8ceecd1ae4c1a13cb10f45c)
Signed-off-by: Michal Simek <michal.simek@xilinx.com> Reviewed-by: Punnaiah Choudary Kalluri <punnaia@xilinx.com>