net: davinci_emac: Round up top tx buffer boundaries for dcache ops

check_cache_range() warns that the top boundaries are not properly
aligned when flushing or invalidating the buffers and make these
operations fail.

This gets rid of the remaining warnings:
CACHE: Misaligned operation at range

Signed-off-by: Karl Beldan <karl.beldan+oss@gmail.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Mugunthan V N <mugunthanvnm@ti.com>

drivers/net/davinci_emac.c

@@ -637,7 +637,7 @@ static int davinci_eth_send_packet (struct eth_device *dev,
 				      EMAC_CPPI_EOP_BIT);
 
 	flush_dcache_range((unsigned long)packet,
-			(unsigned long)packet + length);
+			   (unsigned long)packet + ALIGN(length, PKTALIGN));
 
 	/* Send the packet */
 	writel(BD_TO_HW((unsigned long)emac_tx_desc), &adap_emac->TX0HDP);