ARM: dts: imx6ull: Fix i.MX6ULL/ULZ ocotp compatible

Since imx6ulz.dtsi includes imx6ull.dtsi, we only need to fix the compatible
string here to achieve the correct OTP size for both SoCs.

Signed-off-by: Stefan Wahren <[e-mail]>
Signed-off-by: Shawn Guo <[e-mail]>

arch/arm/boot/dts/imx6ull.dtsi

···
 	>;
 };
 
+&ocotp {
+	compatible = "fsl,imx6ull-ocotp", "syscon";
+};
+
 / {
 	soc {
 		aips3: aips-bus@2200000 {