arm/km: add variable waitforne to mgcoge3un

Add this board specific variable to the default environment
of this board.

Signed-off-by: Holger Brunck <holger.brunck@keymile.com>
Signed-off-by: Valentin Longchamp <valentin.longchamp@keymile.com>
cc: Prafulla Wadaskar <prafulla@marvell.com>

include/configs/mgcoge3un.h

@@ -76,6 +76,8 @@
 	MVGBE_SET_GMII_SPEED_TO_10_100	|\
 	MVGBE_SET_MII_SPEED_TO_100)
 
+#define CONFIG_KM_BOARD_EXTRA_ENV	"waitforne=true\0"
+
 /*
  * PCIe port not used on mgcoge3un
  */