ASoC: z2: Automatically disconnect non-connected pins

Most DAPM input and output pins of the wm8750 are either used in the card's
DAPM routing table or are marked as not connected. The only exceptions are
the LINPUT1, RINPUT1, LINPUT2 input pins. Lets assume that those were
simply overlooked and that the routing table is complete.

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>