raspberrypi: enable ALSA audio

Enable ALSA audio interfaces so that there is direct access to
sound devices e.g. when using SoundEffect.

Change-Id: I58d296cd85f7ba036c93adf24d5a7bcdf17201d4
Fixes: QTBUG-76952
Reviewed-by: Oleksandr Kravchuk <oleksandr.kravchuk@pelagicore.com>
Reviewed-by: Kari Hormi <kari.hormi@qt.io>

meta-boot2qt-distro/conf/distro/include/raspberrypi.inc

@@ -45,6 +45,11 @@ module_conf_bcm2835-v4l2 = "options bcm2835-v4l2 gst_v4l2src_is_broken=1"
 # video camera support
 VIDEO_CAMERA = "1"
 
+RPI_EXTRA_CONFIG = "# \
+Enable the onboard ALSA audio \n\
+dtparam=audio=on \n\
+"
+
 MACHINE_FEATURES += "pitft"
 
 MACHINE_GSTREAMER_1_0_PLUGIN += "gstreamer1.0-omx"