ASoC: dapm: Ensure power gets managed for line widgets

Line widgets had not been included in either the power up or power down
sequences so if a widget had an event associated with it that event would
never be run. Fix this minimally by adding them to the sequences, we
should probably be doing away with the specific widget types as they all
have the same priority anyway.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: stable@vger.kernel.org