clk: si570: Convert to use maple tree register cache

clk: si570: Convert to use maple tree register cache

The maple tree register cache is based on a much more modern data structure
than the rbtree cache and makes optimisation choices which are probably
more appropriate for modern systems than those made by the rbtree cache.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20230929-clk-maple-si-v1-5-e26cfcaf27bd@kernel.org
Signed-off-by: Stephen Boyd <sboyd@kernel.org>