board/km: move ls102xa boards to environment text files

Create a common.env which we can use later on also for other boards.

Signed-off-by: Holger Brunck <holger.brunck@hitachienergy.com>
diff --git a/configs/pg_wcom_seli8_defconfig b/configs/pg_wcom_seli8_defconfig
index 8311b3a..aa74e17 100644
--- a/configs/pg_wcom_seli8_defconfig
+++ b/configs/pg_wcom_seli8_defconfig
@@ -20,7 +20,6 @@
 CONFIG_AHCI=y
 # CONFIG_DEEP_SLEEP is not set
 CONFIG_LAYERSCAPE_NS_ACCESS=y
-CONFIG_KM_DEF_NETDEV="eth2"
 CONFIG_KM_COMMON_ETH_INIT=y
 CONFIG_PIGGY_MAC_ADDRESS_OFFSET=3
 CONFIG_PG_WCOM_UBOOT_UPDATE_SUPPORTED=y
@@ -64,6 +63,7 @@
 CONFIG_MTDPARTS_DEFAULT="mtdparts=60000000.nor:128k(rcw),128k(qe),128k(envred),128k(env),512k(res),1m(u-boot),128k(redenvred),128k(redenv),1m(redu-boot),-(ubi0);68000000.flash:-(ubi1)"
 CONFIG_CMD_UBI=y
 CONFIG_OF_CONTROL=y
+CONFIG_ENV_SOURCE_FILE="pg-wcom-seli8"
 CONFIG_ENV_OVERWRITE=y
 CONFIG_ENV_IS_IN_FLASH=y
 CONFIG_SYS_REDUNDAND_ENVIRONMENT=y