ARM: meson: enable USB DFU + RAM on Amlogic boards with USB Gadget

Enable DFU as an alternate USB boot method when script wasn't
uploaded, this fixes USB full boot on G12/SM1 boards.

Link: https://lore.kernel.org/r/20231023-usb-dfu-boot-v1-4-df9d121c67c1@linaro.org
[narmstrong: remove dfu from ad401]
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
diff --git a/configs/libretech-ac_defconfig b/configs/libretech-ac_defconfig
index 4ed04fa..bc17b42 100644
--- a/configs/libretech-ac_defconfig
+++ b/configs/libretech-ac_defconfig
@@ -32,6 +32,7 @@
 # CONFIG_CMD_BDI is not set
 # CONFIG_CMD_IMI is not set
 CONFIG_CMD_ADC=y
+CONFIG_CMD_DFU=y
 CONFIG_CMD_GPIO=y
 # CONFIG_CMD_LOADS is not set
 CONFIG_CMD_MMC=y
@@ -45,6 +46,7 @@
 CONFIG_ENV_IS_IN_SPI_FLASH=y
 CONFIG_SYS_RELOC_GD_ENV_ADDR=y
 CONFIG_SARADC_MESON=y
+CONFIG_DFU_RAM=y
 CONFIG_MMC_MESON_GX=y
 CONFIG_MTD=y
 CONFIG_DM_MTD=y