ALSA: uapi: Add three missing header files to Kbuild file

include/uapi/sound/Kbuild was missing the inclusion of three header
files in that directory.
Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

include/uapi/sound/Kbuild

 # UAPI Header export list
 header-y += asequencer.h
+header-y += asoc.h
 header-y += asound.h
 header-y += asound_fm.h
 header-y += compress_offload.h
@@ -10,3 +11,5 @@ header-y += hdsp.h
 header-y += hdspm.h
 header-y += sb16_csp.h
 header-y += sfnt_info.h
+header-y += tlv.h
+header-y += usb_stream.h