ASoC: dapm-graph: remove the "ROOT" cluster

Widgets not belonging to any component are currently represented inside a
cluster labeled "ROOT". This is not a correct representation of the actual
structure, as these widgets are not necessarily related to each other as
the ones inside actual components are.

Improve the graphical representation by not adding a cluster around these
widgets. Now a dot cluster represents a card component faithfully. This
will be particularly important with the upcoming improvements which will
visualize the component bias_level.

Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Link: https://patch.msgid.link/20240823-dapm-graph-v1-1-989a47308c4c@bootlin.com


Signed-off-by: Mark Brown <broonie@kernel.org>