ASoC: dapm: Don't mark MICBIAS widgets as auto non-connected

The connected flag of a widget only affects widgets that are either a source
or a sink. The MICBIAS widget is a simple pass-through widget though and
hence its behavior is the same regardless of whether the connected flag is
set or not.

Hence there is not much point in trying to automatically mark MICBIAS
widgets as non-connected, so just remove it.

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