ASoC: poodle: Automatically disconnect non-connected pins

The Zaurus SL-5600 seems to have a microphone input. Otherwise all DAPM
input and output pins of the wm8731 are either used in the card's DAPM
routing table or are marked as not connected.

So add the microphone to the DAPM tables and set the fully_routed flag of
the card instead of manually marking the unused inputs and outputs as not
connected. This makes the code a bit shorter and cleaner.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@kernel.org>