colibri-imx6ull: fix nand bch geometry

Fix NAND BCH geometry as otherwise the following errors are observed
upon boot:

...
Loading Environment from NAND... NAND read from offset 380000 failed -74
...
NAND read from offset 800 failed -74
...
ubi0 error: ubi_io_read: error -74 (ECC error) while reading 64 bytes
 from PEB 0:0, read 64 bytes
...

Fixes: ed48490f8d3f
("mtd: gpmi: fix the bch setting backward compatible issue")
Signed-off-by: Marcel Ziswiler <marcel.ziswiler@toradex.com>
diff --git a/arch/arm/dts/imx6ull-colibri.dts b/arch/arm/dts/imx6ull-colibri.dts
index dbe3e02..d59696e 100644
--- a/arch/arm/dts/imx6ull-colibri.dts
+++ b/arch/arm/dts/imx6ull-colibri.dts
@@ -15,6 +15,7 @@
 &gpmi {
 	pinctrl-names = "default";
 	pinctrl-0 = <&pinctrl_gpmi_nand>;
+	fsl,use-minimum-ecc;
 	nand-on-flash-bbt;
 	nand-ecc-mode = "hw";
 	nand-ecc-strength = <8>;