RPi: add alsa card conf for bcm2835-audio

Signed-off-by: Matthias Reichl <hias@horus.com>

projects/RPi/filesystem/usr/share/alsa/cards/bcm2835_alsa.conf

@@ -0,0 +1,37 @@
+<confdir:pcm/iec958.conf>
+bcm2835_alsa.pcm.iec958.0 {
+    @args [ CARD AES0 AES1 AES2 AES3 ]
+    @args.CARD {
+        type string
+    }
+    @args.AES0 {
+        type integer
+    }
+    @args.AES1 {
+        type integer
+    }
+    @args.AES2 {
+        type integer
+    }
+    @args.AES3 {
+        type integer
+    }
+    type hooks
+    slave.pcm {
+        type hw
+        card $CARD
+        device 1
+    }
+    hooks.0 {
+        type ctl_elems
+        hook_args [
+            {
+                interface PCM
+                name "IEC958 Playback Default"
+                lock true
+                preserve true
+                value [ $AES0 $AES1 $AES2 $AES3 ]
+            }
+        ]
+    }
+}