dt-bindings: i2c: at91: fix i2c-sda-hold-time-ns documentation for sam9x60

SAM9X60 also supports i2c-sda-hold-time-ns. Fix the documentation accordingly.

Fixes: 2034e3f4c9 ("dt-bindings: i2c: at91: add new compatible")
Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Documentation/devicetree/bindings/i2c/i2c-at91.txt

@@ -18,8 +18,10 @@ Optional properties:
 - dma-names: should contain "tx" and "rx".
 - atmel,fifo-size: maximum number of data the RX and TX FIFOs can store for FIFO
   capable I2C controllers.
-- i2c-sda-hold-time-ns: TWD hold time, only available for "atmel,sama5d4-i2c"
-  and "atmel,sama5d2-i2c".
+- i2c-sda-hold-time-ns: TWD hold time, only available for:
+	"atmel,sama5d4-i2c",
+	"atmel,sama5d2-i2c",
+	"microchip,sam9x60-i2c".
 - Child nodes conforming to i2c bus binding
 
 Examples :