imx: imx8mm-icore: migrate to use BINMAN

Use BINMAN instead of imx specific packing method.

Signed-off-by: Peng Fan <peng.fan@nxp.com>
Reviewed-by: Alper Nebi Yasak <alpernebiyasak@gmail.com>
diff --git a/configs/imx8mm-icore-mx8mm-ctouch2_defconfig b/configs/imx8mm-icore-mx8mm-ctouch2_defconfig
index b9fb3c6..cb1a8d4 100644
--- a/configs/imx8mm-icore-mx8mm-ctouch2_defconfig
+++ b/configs/imx8mm-icore-mx8mm-ctouch2_defconfig
@@ -20,7 +20,7 @@
 CONFIG_FIT=y
 CONFIG_FIT_EXTERNAL_OFFSET=0x3000
 CONFIG_SPL_LOAD_FIT=y
-CONFIG_SPL_FIT_GENERATOR="arch/arm/mach-imx/mkimage_fit_atf.sh"
+# CONFIG_USE_SPL_FIT_GENERATOR is not set
 CONFIG_OF_SYSTEM_SETUP=y
 CONFIG_DEFAULT_FDT_FILE="imx8mm-icore-mx8mm-ctouch2.dtb"
 CONFIG_SPL_HAS_BSS_LINKER_SECTION=y