sof-soundwire: Add missing conditional for cs42l43 bridge

sof-soundwire: Add missing conditional for cs42l43 bridge

When adding support for cs42l43 systems without headphones updating the
bridge configuration was missed. Add the missing conditional guard on
the ConflictingDevice which would fail in systems without headphones.

Closes: https://github.com/alsa-project/alsa-ucm-conf/pull/778
Fixes: 7585f5e9671a ("ucm2: sof-soundwire: cs42l43: support UAJ-less configuration")
Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>