riscv: ae350: Switch to use binman to generate u-boot.itb

Use the new BINMAN_STANDALONE_FDT option for AE350 based SPL defconfigs,
so that binman is now used to generate u-boot.itb.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Rick Chen <rick@andestech.com>
diff --git a/configs/ae350_rv64_spl_xip_defconfig b/configs/ae350_rv64_spl_xip_defconfig
index b0afdb4..21b7e88 100644
--- a/configs/ae350_rv64_spl_xip_defconfig
+++ b/configs/ae350_rv64_spl_xip_defconfig
@@ -4,6 +4,7 @@
 CONFIG_ENV_SECT_SIZE=0x1000
 CONFIG_SPL_TEXT_BASE=0x80000000
 CONFIG_SPL=y
+CONFIG_DEFAULT_DEVICE_TREE="ae350_64"
 CONFIG_TARGET_AX25_AE350=y
 CONFIG_ARCH_RV64I=y
 CONFIG_RISCV_SMODE=y
@@ -11,6 +12,7 @@
 CONFIG_DISTRO_DEFAULTS=y
 CONFIG_FIT=y
 CONFIG_SPL_LOAD_FIT_ADDRESS=0x80010000
+# CONFIG_USE_SPL_FIT_GENERATOR is not set
 CONFIG_BOOTDELAY=3
 CONFIG_BOARD_EARLY_INIT_F=y
 CONFIG_SYS_PROMPT="RISC-V # "