overlays: i2c-rtc: add m41t62

Add support for the ST M41T62 real-time clock chip.

Author: ecc1

arch/arm/boot/dts/overlays/README

@@ -689,6 +689,8 @@ Params: abx80x                  Select one of the ABx80x family:
 
         ds3231                  Select the DS3231 device
 
+        m41t62                  Select the M41T62 device
+
         mcp7940x                Select the MCP7940x device
 
         mcp7941x                Select the MCP7941x device

arch/arm/boot/dts/overlays/i2c-rtc-overlay.dts

@@ -143,6 +143,21 @@
 		};
 	};
 
+	fragment@9 {
+		target = <&i2c_arm>;
+		__dormant__ {
+			#address-cells = <1>;
+			#size-cells = <0>;
+			status = "okay";
+
+			m41t62: m41t62@68 {
+				compatible = "st,m41t62";
+				reg = <0x68>;
+				status = "okay";
+			};
+		};
+	};
+
 	__overrides__ {
 		abx80x = <0>,"+0";
 		ds1307 = <0>,"+1";
@@ -153,12 +168,14 @@
 		pcf2127 = <0>,"+6";
 		pcf8523 = <0>,"+7";
 		pcf8563 = <0>,"+8";
+		m41t62 = <0>,"+9";
 		trickle-diode-type = <&abx80x>,"abracon,tc-diode";
 		trickle-resistor-ohms = <&ds1339>,"trickle-resistor-ohms:0",
 					<&abx80x>,"abracon,tc-resistor";
 		wakeup-source = <&ds1339>,"wakeup-source?",
 				<&ds3231>,"wakeup-source?",
 				<&mcp7940x>,"wakeup-source?",
-				<&mcp7941x>,"wakeup-source?";
+				<&mcp7941x>,"wakeup-source?",
+				<&m41t62>,"wakeup-source?";
 	};
 };