ARM: tegra: apalis-eval: Fix backlight PWM comment

Fix the backlight PWM comment as it is actually called PWM_BKL1 rather
than just PWM0.
Signed-off-by: Marcel Ziswiler <marcel.ziswiler@toradex.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

arch/arm/boot/dts/tegra30-apalis-eval.dts

@@ -180,7 +180,7 @@ usb-phy@7d008000 {
 	backlight: backlight {
 		compatible = "pwm-backlight";
 
-		/* PWM0 */
+		/* PWM_BKL1 */
 		pwms = <&pwm 0 5000000>;
 		brightness-levels = <255 231 223 207 191 159 127 0>;
 		default-brightness-level = <6>;