ALSA: remove stale files

Empty files remained likely due to wrong patching.
Remove them now.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
diff --git a/include/sound/ad1848.h b/include/sound/ad1848.h
deleted file mode 100644
index e69de29..0000000
--- a/include/sound/ad1848.h
+++ /dev/null
diff --git a/sound/isa/ad1848/ad1848_lib.c b/sound/isa/ad1848/ad1848_lib.c
deleted file mode 100644
index e69de29..0000000
--- a/sound/isa/ad1848/ad1848_lib.c
+++ /dev/null