dpaa2-eth: Fix compile error due to missing devlink support

The dpaa2 driver depends on devlink, so it should select
NET_DEVLINK in order to fix compile errors, such as:

drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.o: in function `dpaa2_eth_rx_err':
dpaa2-eth.c:(.text+0x3cec): undefined reference to `devlink_trap_report'
drivers/net/ethernet/freescale/dpaa2/dpaa2-eth-devlink.o: in function `dpaa2_eth_dl_info_get':
dpaa2-eth-devlink.c:(.text+0x160): undefined reference to `devlink_info_driver_name_put'

Fixes: ceeb03a ("dpaa2-eth: add basic devlink support")
Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Link: https://lore.kernel.org/r/20201123163553.1666476-1-ciorneiioana@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Author: ezequielgarcia

drivers/net/ethernet/freescale/dpaa2/Kconfig

@@ -5,6 +5,7 @@ config FSL_DPAA2_ETH
 	select PHYLINK
 	select PCS_LYNX
 	select FSL_XGMAC_MDIO
+	select NET_DEVLINK
 	help
 	  This is the DPAA2 Ethernet driver supporting Freescale SoCs
 	  with DPAA2 (DataPath Acceleration Architecture v2).