driver/ldpaa_eth:Flush buffer before seeding BMAN after TX_conf

Flush buffer before releasing to BMan after TX_conf to ensure, the core does
not have any cachelines that the WRIOP will DMA to.

Signed-off-by: Prabhakar Kushwaha <prabhakar@freescale.com>
Reviewed-by: York Sun <yorksun@freescale.com>
diff --git a/drivers/net/ldpaa_eth/ldpaa_eth.c b/drivers/net/ldpaa_eth/ldpaa_eth.c
index d4be1ba..5636511 100644
--- a/drivers/net/ldpaa_eth/ldpaa_eth.c
+++ b/drivers/net/ldpaa_eth/ldpaa_eth.c
@@ -153,6 +153,7 @@
 		}
 	}
 
+	flush_dcache_range(fd_addr, fd_addr + LDPAA_ETH_RX_BUFFER_SIZE);
 	qbman_release_desc_clear(&releasedesc);
 	qbman_release_desc_set_bpid(&releasedesc, dflt_dpbp->dpbp_attr.bpid);
 	do {