configs/imx6-sabreauto: select BR2_TARGET_UBOOT_NEEDS_LZOP

Select BR2_TARGET_UBOOT_NEEDS_LZOP in order to avoid the following
build error on a host machine without lzop installed:

/bin/sh: 1: lzop: not found

Fixes: https://gitlab.com/buildroot.org/buildroot/-/jobs/318105190

Suggested-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Signed-off-by: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

configs/imx6-sabreauto_defconfig

@@ -25,6 +25,7 @@ BR2_TARGET_UBOOT=y
 BR2_TARGET_UBOOT_BOARDNAME="mx6sabreauto"
 BR2_TARGET_UBOOT_CUSTOM_VERSION=y
 BR2_TARGET_UBOOT_CUSTOM_VERSION_VALUE="2019.10"
+BR2_TARGET_UBOOT_NEEDS_LZOP=y
 BR2_TARGET_UBOOT_FORMAT_IMG=y
 BR2_TARGET_UBOOT_SPL=y
 BR2_TARGET_UBOOT_SPL_NAME="SPL"