media: v4l2-common: Always register clock with device-specific name
If we need to register a dummy fixed-frequency clock, always register it
using a device-specific name.
This supports the use case where a system has two of the same sensor,
meaning two instances of the same driver, which previously both tried
(and failed) to create a clock with the same name.
Signed-off-by: Paul Cercueil <paul@crapouillou.net> Reviewed-by: Mehdi Djait <mehdi.djait@linux.intel.com> Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>