ASoC: simple-amplifier: remame dio2125 documentation

The dio2125 is simple enough that we can make it a generic component.
Rename the the dio2125 documentation to simple-amplifier to
prepare this change.
Suggested-by: Nicolò Veronese <nicveronese@gmail.com>
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/sound/dioo,dio2125.txt → Documentation/devicetree/bindings/sound/simple-amplifier.txt

-DIO2125 Audio Driver
+Simple Amplifier Audio Driver
 
 Required properties:
-- compatible : "dioo,dio2125"
-- enable-gpios : the gpio connected to the enable pin of the dio2125
+- compatible : "dioo,dio2125" or "simple-audio-amplifier"
+- enable-gpios : the gpio connected to the enable pin of the simple amplifier
 
 Example:
 
 amp: analog-amplifier {
-	compatible = "dioo,dio2125";
+	compatible = "simple-audio-amplifier";
 	enable-gpios = <&gpio GPIOH_3 0>;
 };