This patch adds a flag for each bug workaround in
tg3_start_xmit_dma_bug().  This is prep work for the following patch.
Signed-off-by: NMatt Carlson <mcarlson@broadcom.com>
Reviewed-by: NMichael Chan <mchan@broadcom.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>