net/ethernet: STMMAC_ETH should depend on HAS_DMA

If NO_DMA=y:

drivers/built-in.o: In function `dma_free_tx_skbufs':
drivers/net/ethernet/stmicro/stmmac/stmmac_main.c:1141: undefined reference to `dma_unmap_single'
drivers/built-in.o: In function `dma_free_rx_skbufs':
drivers/net/ethernet/stmicro/stmmac/stmmac_main.c:1120: undefined reference to `dma_unmap_single'
drivers/built-in.o: In function `free_dma_desc_resources':
drivers/net/ethernet/stmicro/stmmac/stmmac_main.c:1159: undefined reference to `dma_free_coherent'
drivers/built-in.o: In function `stmmac_init_rx_buffers':
drivers/net/ethernet/stmicro/stmmac/stmmac_main.c:980: undefined reference to `dma_map_single'
drivers/built-in.o: In function `init_dma_desc_rings':
drivers/net/ethernet/stmicro/stmmac/stmmac_main.c:1015: undefined reference to `dma_alloc_coherent'
drivers/built-in.o: In function `stmmac_tx_clean':
drivers/net/ethernet/stmicro/stmmac/stmmac_main.c:1250: undefined reference to `dma_unmap_single'
drivers/built-in.o: In function `stmmac_rx':
drivers/net/ethernet/stmicro/stmmac/stmmac_main.c:2044: undefined reference to `dma_unmap_single'
drivers/net/ethernet/stmicro/stmmac/stmmac_main.c:2082: undefined reference to `dma_unmap_single'
drivers/built-in.o: In function `stmmac_rx_refill':
drivers/net/ethernet/stmicro/stmmac/stmmac_main.c:1967: undefined reference to `dma_map_single'
drivers/built-in.o: In function `stmmac_xmit':
drivers/net/ethernet/stmicro/stmmac/stmmac_main.c:1845: undefined reference to `dma_map_single'
drivers/built-in.o: In function `skb_frag_dma_map':
include/linux/skbuff.h:2184: undefined reference to `dma_map_page'
drivers/built-in.o: In function `stmmac_jumbo_frm':
drivers/net/ethernet/stmicro/stmmac/ring_mode.c:40: undefined reference to `dma_map_single'
drivers/built-in.o: In function `stmmac_jumbo_frm':
drivers/net/ethernet/stmicro/stmmac/chain_mode.c:48: undefined reference to `dma_map_single'
drivers/net/ethernet/stmicro/stmmac/chain_mode.c:55: undefined reference to `dma_map_single'

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: netdev@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>