ALSA: Remove deprecated include/sound/driver.h

Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/include/sound/driver.h b/include/sound/driver.h
deleted file mode 100644
index f035943..0000000
--- a/include/sound/driver.h
+++ /dev/null
@@ -1 +0,0 @@
-#warning "This file is deprecated"