dt-bindings: interrupt-controller: New binding for the meson sm1 SoCs

Update the dt-binding to add support for the sm1 SoC family in the
amlogic GPIO interrupt controller driver.
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20190829161635.25067-2-jbrunet@baylibre.com

Documentation/devicetree/bindings/interrupt-controller/amlogic,meson-gpio-intc.txt

@@ -16,6 +16,7 @@ Required properties:
     "amlogic,meson-gxl-gpio-intc" for GXL SoCs (S905X, S912)
     "amlogic,meson-axg-gpio-intc" for AXG SoCs (A113D, A113X)
     "amlogic,meson-g12a-gpio-intc" for G12A SoCs (S905D2, S905X2, S905Y2)
+    "amlogic,meson-sm1-gpio-intc" for SM1 SoCs (S905D3, S905X3, S905Y3)
 - reg : Specifies base physical address and size of the registers.
 - interrupt-controller : Identifies the node as an interrupt controller.
 - #interrupt-cells : Specifies the number of cells needed to encode an