include/linux/usb/Kbuild - linux-imx - Git at Google

 unifdef-y += audio.h
 unifdef-y += cdc.h
 unifdef-y += ch9.h
 unifdef-y += gadgetfs.h
 unifdef-y += midi.h
	unifdef-y += audio.h
	unifdef-y += cdc.h
	unifdef-y += ch9.h
	unifdef-y += gadgetfs.h
	unifdef-y += midi.h