ASoC: Intel: byt-max98090: Set card as fully routed

All byt-max98090 audio connections are known and described in DAPM routing
table. Set the fully_routed flag in order to disable unused codec pins.

Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>