arm: socfpga: Use DM watchdog timer

All SoCFPGA platforms (except Cyclone V) are now switching
to CONFIG_WDT (driver model for watchdog timer drivers)
from CONFIG_HW_WATCHDOG.

Signed-off-by: Chee Hong Ang <chee.hong.ang@intel.com>
Reviewed-by: Ley Foon Tan <ley.foon.tan@intel.com>
diff --git a/arch/arm/dts/socfpga_agilex_socdk-u-boot.dtsi b/arch/arm/dts/socfpga_agilex_socdk-u-boot.dtsi
index debeb8b..6cac36a 100644
--- a/arch/arm/dts/socfpga_agilex_socdk-u-boot.dtsi
+++ b/arch/arm/dts/socfpga_agilex_socdk-u-boot.dtsi
@@ -40,3 +40,7 @@
 &qspi {
 	status = "okay";
 };
+
+&watchdog0 {
+	u-boot,dm-pre-reloc;
+};