board: toradex: colibri-imx(6ull|imx7): Fix missing fdt_fixup boot error

In commit 51aaaf5e7975 ("board: toradex: imx: Remove not needed env variables")
the empty definition of fdt_fixup variable was removed, however this was
still referenced from the boot command leading to boot failures:
 ## Error: \"fdt_fixup\" not defined`

Fix this by removing "run fdt_fixup" from the boot command and instead
enable CONFIG_OF_ENV_SETUP in the defconfig that would achieve the same
but in a more robust way (it works fine even if the variable is not
defined).

Fixes: 51aaaf5e7975 ("board: toradex: imx: Remove not needed env variables")
Signed-off-by: Francesco Dolcini <francesco.dolcini@toradex.com>
diff --git a/configs/colibri-imx6ull_defconfig b/configs/colibri-imx6ull_defconfig
index fc10d7f..4a0ff02 100644
--- a/configs/colibri-imx6ull_defconfig
+++ b/configs/colibri-imx6ull_defconfig
@@ -18,6 +18,7 @@
 CONFIG_FIT_VERBOSE=y
 CONFIG_DISTRO_DEFAULTS=y
 CONFIG_BOOTDELAY=1
+CONFIG_OF_ENV_SETUP=y
 CONFIG_BOOTCOMMAND="run ubiboot || run distro_bootcmd;"
 CONFIG_USE_PREBOOT=y
 CONFIG_PREBOOT="test -n ${fdtfile} || setenv fdtfile imx6ull-colibri${variant}-${fdt_board}.dtb"
diff --git a/configs/colibri_imx7_defconfig b/configs/colibri_imx7_defconfig
index 454fb9b..47c2ffc 100644
--- a/configs/colibri_imx7_defconfig
+++ b/configs/colibri_imx7_defconfig
@@ -19,6 +19,7 @@
 CONFIG_FIT_VERBOSE=y
 CONFIG_DISTRO_DEFAULTS=y
 CONFIG_BOOTDELAY=1
+CONFIG_OF_ENV_SETUP=y
 CONFIG_BOOTCOMMAND="run ubiboot ; echo ; echo ubiboot failed ; run distro_bootcmd;"
 CONFIG_USE_PREBOOT=y
 CONFIG_PREBOOT="test -n ${fdtfile} || setenv fdtfile ${soc}-colibri-${fdt_board}.dtb "
diff --git a/include/configs/colibri-imx6ull.h b/include/configs/colibri-imx6ull.h
index 7c9d633..8860cee 100644
--- a/include/configs/colibri-imx6ull.h
+++ b/include/configs/colibri-imx6ull.h
@@ -53,7 +53,7 @@
 		"ubi part ubi &&" \
 		"ubi read ${kernel_addr_r} kernel && " \
 		"ubi read ${fdt_addr_r} dtb && " \
-		"run fdt_fixup && bootz ${kernel_addr_r} - ${fdt_addr_r}\0" \
+		"bootz ${kernel_addr_r} - ${fdt_addr_r}\0" \
 
 #if defined(CONFIG_TARGET_COLIBRI_IMX6ULL_NAND)
 /* Run Distro Boot script if ubiboot fails */
diff --git a/include/configs/colibri_imx7.h b/include/configs/colibri_imx7.h
index c34f1f9..33133a0b 100644
--- a/include/configs/colibri_imx7.h
+++ b/include/configs/colibri_imx7.h
@@ -94,7 +94,7 @@
 		"ubi part ubi && run m4boot && " \
 		"ubi read ${kernel_addr_r} kernel && " \
 		"ubi read ${fdt_addr_r} dtb && " \
-		"run fdt_fixup && bootz ${kernel_addr_r} - ${fdt_addr_r}\0" \
+		"bootz ${kernel_addr_r} - ${fdt_addr_r}\0" \
 
 #if defined(CONFIG_TARGET_COLIBRI_IMX7_NAND)
 #define MODULE_EXTRA_ENV_SETTINGS \