ARM: tegra: colibri_t30: annotate power I2C being on-module

The power I2C bus aka PWR_I2C which connects to the audio codec, PMIC,
temperature sensor and touch screen controller is really on-module only.
Signed-off-by: Marcel Ziswiler <marcel.ziswiler@toradex.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

arch/arm/boot/dts/tegra30-colibri.dtsi

@@ -713,7 +713,7 @@ hdmi_ddc: i2c@7000c700 {
 
 	/*
 	 * PWR_I2C: power I2C to audio codec, PMIC, temperature sensor and
-	 * touch screen controller
+	 * touch screen controller (On-module)
 	 */
 	i2c@7000d000 {
 		status = "okay";