ARC: [plat-arcfpga] Enable arc_emac for ARCAngle4 Board

* Add arc_emac to DeviceTree DT description
  "Documentation/devicetree/bindings/net/arc_emac.txt".

* Update defconfig correspondingly

[vgupta: tweaked changelog]
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
diff --git a/arch/arc/configs/fpga_defconfig b/arch/arc/configs/fpga_defconfig
index 95350be6..2c8ee30 100644
--- a/arch/arc/configs/fpga_defconfig
+++ b/arch/arc/configs/fpga_defconfig
@@ -38,6 +38,9 @@
 # CONFIG_PREVENT_FIRMWARE_BUILD is not set
 # CONFIG_FIRMWARE_IN_KERNEL is not set
 # CONFIG_BLK_DEV is not set
+CONFIG_NETDEVICES=y
+CONFIG_ARC_EMAC=y
+CONFIG_LXT_PHY=y
 # CONFIG_INPUT_MOUSEDEV_PSAUX is not set
 # CONFIG_INPUT_KEYBOARD is not set
 # CONFIG_INPUT_MOUSE is not set