ALSA: doc: Fix missing "I" for kerneldoc inclusion

Fixes: 90446d07 ('ALSA: doc: Add missing headers and compress stuff to alsa-driver-api.tmpl')
Signed-off-by: Takashi Iwai <tiwai@suse.de>

Documentation/DocBook/alsa-driver-api.tmpl

@@ -57,7 +57,7 @@
 !Esound/core/pcm.c
 !Esound/core/pcm_lib.c
 !Esound/core/pcm_native.c
-!include/sound/pcm.h
+!Iinclude/sound/pcm.h
      </sect1>
      <sect1><title>PCM Format Helpers</title>
 !Esound/core/pcm_misc.c