imx8ulp_evk: enable binman support

Enable binman support and add documentation for the
imx8ul-evk board.

Signed-off-by: Gary Bisson <bisson.gary@gmail.com>
diff --git a/configs/imx8ulp_evk_defconfig b/configs/imx8ulp_evk_defconfig
index b302df1..0f0748b 100644
--- a/configs/imx8ulp_evk_defconfig
+++ b/configs/imx8ulp_evk_defconfig
@@ -8,7 +8,7 @@
 CONFIG_SF_DEFAULT_SPEED=40000000
 CONFIG_ENV_SIZE=0x2000
 CONFIG_ENV_OFFSET=0x400000
-CONFIG_IMX_CONFIG=""
+CONFIG_IMX_CONFIG="arch/arm/mach-imx/imx8ulp/imximage.cfg"
 CONFIG_DM_GPIO=y
 CONFIG_DEFAULT_DEVICE_TREE="imx8ulp-evk"
 CONFIG_SPL_TEXT_BASE=0x22020000
@@ -38,6 +38,7 @@
 CONFIG_SPL_BOARD_INIT=y
 CONFIG_SPL_BOOTROM_SUPPORT=y
 CONFIG_SPL_LOAD_IMX_CONTAINER=y
+CONFIG_IMX_CONTAINER_CFG="arch/arm/mach-imx/imx8ulp/container.cfg"
 # CONFIG_SPL_SHARES_INIT_SP_ADDR is not set
 CONFIG_SPL_SYS_MALLOC=y
 CONFIG_SPL_HAS_CUSTOM_MALLOC_START=y