pico-imx7d: Enable DM_USB

This patch enable usb support with device-tree

Signed-off-by: Joris Offouga <offougajoris@gmail.com>
Reviewed-by: Jun Nie <jun.nie@linaro.org>
diff --git a/configs/pico-pi-imx7d_defconfig b/configs/pico-pi-imx7d_defconfig
index 14c0817..7689242 100644
--- a/configs/pico-pi-imx7d_defconfig
+++ b/configs/pico-pi-imx7d_defconfig
@@ -51,6 +51,7 @@
 CONFIG_FASTBOOT_CMD_OEM_FORMAT=y
 CONFIG_DM_GPIO=y
 CONFIG_DM_MMC=y
+CONFIG_DM_USB=y
 CONFIG_SUPPORT_EMMC_BOOT=y
 CONFIG_FSL_ESDHC_IMX=y
 CONFIG_PHYLIB=y