ARM: tegra: colibri_t20: rename ac97 label to tegra_ac97

Rename ac97 label to tegra_ac97 to be more in-line with the device tree
binding documentation.
Signed-off-by: Marcel Ziswiler <marcel.ziswiler@toradex.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

arch/arm/boot/dts/tegra20-colibri.dtsi

@@ -418,7 +418,7 @@ lvp0 {
 		};
 	};
 
-	ac97: ac97@70002000 {
+	tegra_ac97: ac97@70002000 {
 		status = "okay";
 		nvidia,codec-reset-gpio =
 			<&gpio TEGRA_GPIO(V, 0) GPIO_ACTIVE_HIGH>;
@@ -734,7 +734,7 @@ sound {
 			"LineIn", "LINEINL",
 			"LineIn", "LINEINR",
 			"Mic", "MIC1";
-		nvidia,ac97-controller = <&ac97>;
+		nvidia,ac97-controller = <&tegra_ac97>;
 		clocks = <&tegra_car TEGRA20_CLK_PLL_A>,
 			 <&tegra_car TEGRA20_CLK_PLL_A_OUT0>,
 			 <&tegra_car TEGRA20_CLK_CDEV1>;