bnxt: add dma mapping attributes

bnxt: add dma mapping attributes

On the SPARC platform we need to use the DMA_ATTR_WEAK_ORDERING
attribute in our dma mapping in order to get the expected performance
out of the receive path.  Setting this boosts a simple iperf receive
session from 2 Gbe to 23.4 Gbe.

Orabug: 26366387

Signed-off-by: Shannon Nelson <shannon.nelson@oracle.com>
Reviewed-by: Tushar Dave <tushar.n.dave@oracle.com>
Reviewed-by: Tom Saeger <tom.saeger@oracle.com>
Signed-off-by: Allen Pais <allen.pais@oracle.com>
Signed-off-by: Brian Maly <brian.maly@oracle.com>
Conflicts:
	drivers/net/ethernet/broadcom/bnxt/bnxt.c
Signed-off-by: Somasundaram Krishnasamy <somasundaram.krishnasamy@oracle.com>