dt-bindings: opp-v2: Fix clock-latency-ns prop in example

Accidentally discovered a hidden typo in the DT-nodes defined in the
opp-v2 bindings example. Instead of specifying the "clock-latency-ns"
property the DT-node has been created with the "lock-latency-ns" property
in it, which doesn't exist neither in opp-v2 nor in the base schemas.
Let's fix the name to having the "clock-" prefix as it was originally
implied and as the rest of the similar nodes has.

Fixes: 94274f20 ("dt-bindings: opp: Convert to DT schema")
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>