rtc: ds1307: remove legacy check for "isil, irq2-can-wakeup-machine" property

Commit 8b44f5be ("ARM: dts: armada: replace isil,irq2-can-wakeup-machine with wakeup-source property")
removed the last usage of "isil,irq2-can-wakeup-machine" almost
two years ago. So I think we can get rid of supporting this
legacy binding.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

Documentation/devicetree/bindings/power/wakeup-source.txt

@@ -20,13 +20,12 @@ List of legacy properties and respective binding document
 1. "enable-sdio-wakeup"		Documentation/devicetree/bindings/mmc/mmc.txt
 2. "gpio-key,wakeup"		Documentation/devicetree/bindings/input/gpio-keys{,-polled}.txt
 3. "has-tpo"			Documentation/devicetree/bindings/rtc/rtc-opal.txt
-4. "isil,irq2-can-wakeup-machine" Documentation/devicetree/bindings/rtc/isil,isl12057.txt
-5. "linux,wakeup"		Documentation/devicetree/bindings/input/gpio-matrix-keypad.txt
+4. "linux,wakeup"		Documentation/devicetree/bindings/input/gpio-matrix-keypad.txt
 				Documentation/devicetree/bindings/mfd/tc3589x.txt
 				Documentation/devicetree/bindings/input/ads7846.txt
-6. "linux,keypad-wakeup"	Documentation/devicetree/bindings/input/qcom,pm8xxx-keypad.txt
-7. "linux,input-wakeup"		Documentation/devicetree/bindings/input/samsung-keypad.txt
-8. "nvidia,wakeup-source"	Documentation/devicetree/bindings/input/nvidia,tegra20-kbc.txt
+5. "linux,keypad-wakeup"	Documentation/devicetree/bindings/input/qcom,pm8xxx-keypad.txt
+6. "linux,input-wakeup"		Documentation/devicetree/bindings/input/samsung-keypad.txt
+7. "nvidia,wakeup-source"	Documentation/devicetree/bindings/input/nvidia,tegra20-kbc.txt
 
 Examples
 --------

Documentation/devicetree/bindings/rtc/isil,isl12057.txt

@@ -24,7 +24,6 @@ Optional properties:
 
  - "wakeup-source": mark the chip as a wakeup source, independently of
     the availability of an IRQ line connected to the SoC.
-    (Legacy property supported: "isil,irq2-can-wakeup-machine")
 
  - "interrupt-parent", "interrupts": for passing the interrupt line
    of the SoC connected to IRQ#2 of the RTC chip.

drivers/rtc/rtc-ds1307.c

@@ -1388,14 +1388,8 @@ static int ds1307_probe(struct i2c_client *client,
  * This will guarantee the 'wakealarm' sysfs entry is available on the device,
  * if supported by the RTC.
  */
-	if (of_property_read_bool(client->dev.of_node, "wakeup-source")) {
+	if (of_property_read_bool(client->dev.of_node, "wakeup-source"))
 		ds1307_can_wakeup_device = true;
-	}
-	/* Intersil ISL12057 DT backward compatibility */
-	if (of_property_read_bool(client->dev.of_node,
-				  "isil,irq2-can-wakeup-machine")) {
-		ds1307_can_wakeup_device = true;
-	}
 #endif
 
 	switch (ds1307->type) {