toradex: imx6*: fix reset using wdt-reboot driver

commit 68dcbdd594d4 ("ARM: imx: Add weak default reset_cpu()")
introduced a regression that 'reset' command unable to reset
imx6 and imx6ull based Toradex's modules in the u-boot.

This change enables a watchdog-based sysreset driver for
Toradex's colibri-imx6, colibri-imx6ull (with nand and emmc)
and apalis-imx6 which solves the reset command regression on
these modules.

Acked-by: Marcel Ziswiler <marcel.ziswiler@toradex.com>
Fixes: 68dcbdd594d4 ("ARM: imx: Add weak default reset_cpu()")
Signed-off-by: Parth Pancholi <parth.pancholi@toradex.com>
Signed-off-by: Francesco Dolcini <francesco.dolcini@toradex.com>
Reviewed-by: Fabio Estevam <festevam@gmail.com>
diff --git a/arch/arm/dts/imx6ull-colibri-eval-v3-u-boot.dtsi b/arch/arm/dts/imx6ull-colibri-eval-v3-u-boot.dtsi
index 7318142..8494b1a 100644
--- a/arch/arm/dts/imx6ull-colibri-eval-v3-u-boot.dtsi
+++ b/arch/arm/dts/imx6ull-colibri-eval-v3-u-boot.dtsi
@@ -13,6 +13,12 @@
 	sysinfo {
 		compatible = "toradex,sysinfo";
 	};
+
+	wdt-reboot {
+		compatible = "wdt-reboot";
+		wdt = <&wdog1>;
+		bootph-pre-ram;
+	};
 };
 
 &pinctrl_uart1 {
@@ -58,3 +64,7 @@
 		};
 	};
 };
+
+&wdog1 {
+	bootph-pre-ram;
+};