ASoC: rt5640: Revise the input pin name of IN1 and IN2 in document of the devicetree

Signed-off-by: Oder Chiou <oder_chiou@realtek.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
diff --git a/Documentation/devicetree/bindings/sound/rt5640.txt b/Documentation/devicetree/bindings/sound/rt5640.txt
index bac4d9a..5d062a5 100644
--- a/Documentation/devicetree/bindings/sound/rt5640.txt
+++ b/Documentation/devicetree/bindings/sound/rt5640.txt
@@ -24,9 +24,9 @@
   * DMIC2
   * MICBIAS1
   * IN1P
-  * IN1R
+  * IN1N
   * IN2P
-  * IN2R
+  * IN2N
   * HPOL
   * HPOR
   * LOUTL