[ALSA] fix improper CONFIG_SND_MAJOR usage

Modules: HWDEP Midlevel,PCM Midlevel,RawMidi Midlevel,ALSA Core

Replace usage of CONFIG_SND_MAJOR with snd_major, where appropriate.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
diff --git a/include/sound/core.h b/include/sound/core.h
index 642ddfb..2be65ad 100644
--- a/include/sound/core.h
+++ b/include/sound/core.h
@@ -255,6 +255,7 @@
 
 /* sound.c */
 
+extern int snd_major;
 extern int snd_ecards_limit;
 
 void snd_request_card(int card);