media: camss: Unify the clock names

Use more logical clock names - similar to the names in documentation.
This will allow better handling of the clocks in the driver when support
for more hardware versions is added - equivalent clocks on different
hardware versions will have the same name.

Signed-off-by: Todor Tomov <todor.tomov@linaro.org>
Signed-off-by: Hans Verkuil <hansverk@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>