Can any other Hifiberry user confirm they have working audio?Your kodi log doesn't have debug enabled.
You could try a Milhouse/nightly build as I have seen recent reports of I2S audio working with it:
LibreELEC Testbuilds for RaspberryPi (Kodi 17.0)
I have a working Hifiberry dac-plus on my Rpi2, I had also problems with it.
My problem was solved after installing the updater of same version as the LE installation installed on my Rpi.
Kind regards,
Rob