km/boards: fix typo for MAC address offset config option

This patch only fixes a typo.

Signed-off-by: Holger Brunck <holger.brunck@ch.abb.com>
CC: Stefan Roese <sr@denx.de>
CC: Valentin Longchamp <valentin.longchamp@ch.abb.com>
Reviewed-by: Stefan Roese <sr@denx.de>
diff --git a/configs/kmcoge5un_defconfig b/configs/kmcoge5un_defconfig
index a1be25c..80a7555 100644
--- a/configs/kmcoge5un_defconfig
+++ b/configs/kmcoge5un_defconfig
@@ -4,7 +4,7 @@
 CONFIG_KIRKWOOD=y
 CONFIG_SYS_TEXT_BASE=0x07d00000
 CONFIG_TARGET_KM_KIRKWOOD=y
-CONFIG_PIGGY_MAC_ADRESS_OFFSET=3
+CONFIG_PIGGY_MAC_ADDRESS_OFFSET=3
 CONFIG_KM_ENV_IS_IN_SPI_NOR=y
 CONFIG_KM_PIGGY4_88E6352=y
 CONFIG_ENV_SIZE=0x2000