Watchdog: Support WDIOF_CARDRESET on TI AM65x platform

To have the WDIOF_CARDRESET support for the TI AM65x platform watchdog,
this patch reserves some memories, which indicate if the current boot due
to a watchdog reset.

Signed-off-by: Li Hua Qian <huaqian.li@siemens.com>
diff --git a/arch/arm/dts/k3-am65-iot2050-common.dtsi b/arch/arm/dts/k3-am65-iot2050-common.dtsi
index 65da226..b6135b8 100644
--- a/arch/arm/dts/k3-am65-iot2050-common.dtsi
+++ b/arch/arm/dts/k3-am65-iot2050-common.dtsi
@@ -64,6 +64,12 @@
 			alignment = <0x1000>;
 			no-map;
 		};
+
+		/* To reserve the power-on(PON) reason for watchdog reset */
+		wdt_reset_memory_region: wdt-memory@a2200000 {
+			reg = <0x00 0xa2200000 0x00 0x00001000>;
+			no-map;
+		};
 	};
 
 	leds {
@@ -720,6 +726,11 @@
 	mboxes = <&mailbox0_cluster1 &mbox_mcu_r5fss0_core1>;
 };
 
+&mcu_rti1 {
+	memory-region = <&wdt_reset_memory_region>;
+
+};
+
 &icssg0_mdio {
 	status = "disabled";
 };