clk: amlogic: get regmap with clk_regmap_init

clk: amlogic: get regmap with clk_regmap_init

Add clk_regmap_init() and use it with all clock types which derive from
clk_regmap. This helps initialise clk_regmap clocks without requiring
tables to keep track of the clock using this type.

The way it is done couples clk_regmap with the controllers, which is not
ideal. This is a temporary solution to get rid of the tables. The situation
will eventually be improved.

Link: https://lore.kernel.org/r/20250623-amlogic-clk-drop-clk-regmap-tables-v4-1-ff04918211cc@baylibre.com
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>