media: v4l2-fwnode: Use debug level for printing link frequencies

pr_info() was accidentally used to print the link frequencies whereas the
rest of the information is printed on debug level. Fix that by using
pr_debug() also for link frequencies.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>