clk: meson: gxbb-aoclk: migrate to the new parent description method

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>