V4L/DVB (9588): Don't load em28xx audio module for digital-only devices

Rework the logic so that the em28xx-alsa module does not get loaded for devices
that don't support analog audio (such as the em2874)

Signed-off-by: Devin Heitmueller <devin.heitmueller@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/video/em28xx/em28xx.h b/drivers/media/video/em28xx/em28xx.h
index 326208a..7bf08ce 100644
--- a/drivers/media/video/em28xx/em28xx.h
+++ b/drivers/media/video/em28xx/em28xx.h
@@ -376,6 +376,7 @@
 	unsigned int has_tda9887:1;
 	unsigned int stream_on:1;	/* Locks streams */
 	unsigned int has_audio_class:1;
+	unsigned int has_alsa_audio:1;
 	unsigned int has_12mhz_i2s:1;
 	unsigned int max_range_640_480:1;
 	unsigned int has_dvb:1;