stmmac: make function tables const

These tables only contain function pointers.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Acked-by: Gustavo F. Padovan <padovan@profusion.mobi>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/stmmac/dwmac1000_dma.c b/drivers/net/stmmac/dwmac1000_dma.c
index ce6163e..2c47712 100644
--- a/drivers/net/stmmac/dwmac1000_dma.c
+++ b/drivers/net/stmmac/dwmac1000_dma.c
@@ -138,7 +138,7 @@
 	}
 }
 
-struct stmmac_dma_ops dwmac1000_dma_ops = {
+const struct stmmac_dma_ops dwmac1000_dma_ops = {
 	.init = dwmac1000_dma_init,
 	.dump_regs = dwmac1000_dump_dma_regs,
 	.dma_mode = dwmac1000_dma_operation_mode,