dt: fsl-imx-cspi.txt: Fix comment about GPIOs used for chip selects

The gpio numbers does not match the comment.

Fix the comments for GPIOs used for chip selects.
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NRob Herring <rob.herring@calxeda.com>

Documentation/devicetree/bindings/spi/fsl-imx-cspi.txt

@@ -17,6 +17,6 @@ ecspi@70010000 {
 	reg = <0x70010000 0x4000>;
 	interrupts = <36>;
 	fsl,spi-num-chipselects = <2>;
-	cs-gpios = <&gpio3 24 0>, /* GPIO4_24 */
-		   <&gpio3 25 0>; /* GPIO4_25 */
+	cs-gpios = <&gpio3 24 0>, /* GPIO3_24 */
+		   <&gpio3 25 0>; /* GPIO3_25 */
 };