This clock controller use the string comparison method to describe parent
relation between the clocks, which is not optimized.

Migrate to the new way by using .parent_hws where possible (when parent
clocks are localy declared in the controller) and use .parent_data
otherwise.

Remove clk input helper and all bypass clocks (declared in probe function)
which are no longer used since we are able to use device-tree clock name
directly.
Signed-off-by: Alexandre Mergnat <amergnat@baylibre.com>
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>