dt-bindings: atmel-isi: add microchip,sam9x60-isi

Add microchip,sam9x60-isi to DT bindings documentation.
Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Link: https://lore.kernel.org/r/1578673089-3484-6-git-send-email-claudiu.beznea@microchip.comSigned-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Documentation/devicetree/bindings/media/atmel-isi.txt

@@ -2,7 +2,7 @@ Atmel Image Sensor Interface (ISI)
 ----------------------------------
 
 Required properties for ISI:
-- compatible: must be "atmel,at91sam9g45-isi".
+- compatible: must be "atmel,at91sam9g45-isi" or "microchip,sam9x60-isi".
 - reg: physical base address and length of the registers set for the device.
 - interrupts: should contain IRQ line for the ISI.
 - clocks: list of clock specifiers, corresponding to entries in the clock-names