net: designware: socfpga: Add Arria10 extras

Add wrapper around the designware MAC driver to handle the SoCFPGA
specific configuration bits. On Arria10, this is configuration of
syscon phy_intf.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Chin Liang See <chin.liang.see@intel.com>
Cc: Dinh Nguyen <dinguyen@kernel.org>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Joe Hershberger <joe.hershberger@ni.com>
diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig
index f762b08..d86da77 100644
--- a/drivers/net/Kconfig
+++ b/drivers/net/Kconfig
@@ -150,6 +150,14 @@
 	  100Mbit and 1 Gbit operation. You must enable CONFIG_PHYLIB to
 	  provide the PHY (physical media interface).
 
+config ETH_DESIGNWARE_SOCFPGA
+	bool "Altera SoCFPGA extras for Synopsys Designware Ethernet MAC"
+	depends on DM_ETH && ETH_DESIGNWARE
+	help
+	  The Altera SoCFPGA requires additional configuration of the
+	  Altera system manager to correctly interface with the PHY.
+	  This code handles those SoC specifics.
+
 config ETHOC
 	bool "OpenCores 10/100 Mbps Ethernet MAC"
 	help