au1000_eth: Fix warnings.

Fixed by including <linux/dma-mapping.h>:

  CC      drivers/net/au1000_eth.o
drivers/net/au1000_eth.c: In function 'au1000_probe':
drivers/net/au1000_eth.c:661: warning: implicit declaration of function 'dma_alloc_noncoherent'
drivers/net/au1000_eth.c:802: warning: implicit declaration of function 'dma_free_noncoherent'
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

drivers/net/au1000_eth.c

@@ -34,7 +34,7 @@
  *
  *
  */
-
+#include <linux/dma-mapping.h>
 #include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/string.h>