dt-bindings: iio: adc: at91-sama5d2_adc: add id for temperature channel

Add ID for temperature channel of AT91 SAMA5D2 ADC.
Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220803102855.2191070-17-claudiu.beznea@microchip.comSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

include/dt-bindings/iio/adc/at91-sama5d2_adc.h

@@ -13,4 +13,7 @@
 /* pressure channel index */
 #define AT91_SAMA5D2_ADC_P_CHANNEL		26
 
+/* SAMA7G5 Temperature sensor channel index. */
+#define AT91_SAMA7G5_ADC_TEMP_CHANNEL		31
+
 #endif