ASoC: Intel: cht-bsw-rt5672: Add key-mappings for the headset buttons

Having the headset buttons send BTN_0, BTN_1 and BTN_2 events is not
really useful. Add mappings to PLAYPAUSE VOLUME_UP and VOLUME_DOWN like
we do in other Intel machine drivers.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/intel/boards/cht_bsw_rt5672.c

@@ -16,6 +16,7 @@
  *  General Public License for more details.
  */
 
+#include <linux/input.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>
@@ -212,6 +213,10 @@ static int cht_codec_init(struct snd_soc_pcm_runtime *runtime)
         if (ret)
                 return ret;
 
+	snd_jack_set_key(ctx->headset.jack, SND_JACK_BTN_0, KEY_PLAYPAUSE);
+	snd_jack_set_key(ctx->headset.jack, SND_JACK_BTN_1, KEY_VOLUMEUP);
+	snd_jack_set_key(ctx->headset.jack, SND_JACK_BTN_2, KEY_VOLUMEDOWN);
+
 	rt5670_set_jack_detect(component, &ctx->headset);
 	if (ctx->mclk) {
 		/*