arm64: ls1046ardb: Add distro boot support

Tested on ls1046ardb with automatically boot Ubuntu from SD card or
USB disk, if it fails to detect external storage disk, fall back to
qspi boot.

Signed-off-by: Shengzhou Liu <Shengzhou.Liu@nxp.com>
Signed-off-by: Gong Qianyu <Qianyu.Gong@nxp.com>
Reviewed-by: York Sun <york.sun@nxp.com>
diff --git a/configs/ls1046ardb_qspi_defconfig b/configs/ls1046ardb_qspi_defconfig
index 1127355..12a0e92 100644
--- a/configs/ls1046ardb_qspi_defconfig
+++ b/configs/ls1046ardb_qspi_defconfig
@@ -36,3 +36,4 @@
 CONFIG_FSL_QSPI=y
 CONFIG_USB=y
 CONFIG_DM_USB=y
+CONFIG_DISTRO_DEFAULTS=y