[D18] enable SECO_ECOSYSTEM flag, resize u-boot environment

configs/seco_imx8mp_d18_defconfig

@@ -8,8 +8,8 @@ CONFIG_SYS_MALLOC_F_LEN=0x10000
 CONFIG_NR_DRAM_BANKS=3
 CONFIG_SYS_MEMTEST_START=0x60000000
 CONFIG_SYS_MEMTEST_END=0xC0000000
-CONFIG_ENV_SIZE=0x4000
-CONFIG_ENV_OFFSET=0x400000
+CONFIG_ENV_SIZE=0x2000
+CONFIG_ENV_OFFSET=0x380000
 CONFIG_ENV_SECT_SIZE=0x10000
 CONFIG_SYS_I2C_MXC_I2C1=y
 CONFIG_SYS_I2C_MXC_I2C2=y
@@ -159,6 +159,8 @@ CONFIG_EFI_SECURE_BOOT=y
 
 # SECO
 CONFIG_SECO_ENV_MANAGER=y
+CONFIG_SECO_ECOSYSTEM=y
+CONFIG_SECO_ECOSYSTEM_TARGET="d18"
 CONFIG_CMD_FS_GENERIC=y
 CONFIG_PHY_TI=y
 CONFIG_NET_RANDOM_ETHADDR=y