dt-bindings/bcm2836-l1-intc: Add interrupt polarity support

This increases the interrupt cells for the 1st level interrupt controller
binding in order to describe the polarity like on the other ARM platforms.

Reviewed-by: Rob Herring <[e-mail]>
Signed-off-by: Stefan Wahren <[e-mail]>
Signed-off-by: Marc Zyngier <[e-mail]>

Documentation/devicetree/bindings/interrupt-controller/brcm,bcm2836-l1-intc.txt

···
 			  registers
 - interrupt-controller:	Identifies the node as an interrupt controller
 - #interrupt-cells:	Specifies the number of cells needed to encode an
-			  interrupt source. The value shall be 1
+			  interrupt source. The value shall be 2
 
 Please refer to interrupts.txt in this directory for details of the common
 Interrupt Controllers bindings used by client devices.
···
 	compatible = "brcm,bcm2836-l1-intc";
 	reg = <0x40000000 0x100>;
 	interrupt-controller;
-	#interrupt-cells = <1>;
+	#interrupt-cells = <2>;
 	interrupt-parent = <&local_intc>;
 };