ASoC: SOF: bump to ABI 3.6

We had a couple of misses with ABI changes, e.g. for Xtensa oops
information and the integration of sound trigger, before we set-up a
formal process to track evolutions.

With this patch, the SOF kernel patches are officially aligned with
the firmware 3.6 level. Changing this level has no impact on existing
users and is fully backwards-compatible.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>