clk: meson: migrate to devm_of_clk_add_hw_provider API

There is a protential memory leak, as of_clk_del_provider is
never called if of_clk_add_hw_provider has been executed.
Fix this by using devm variant API.

Fixes: f8c11f79 ("clk: meson: Add GXBB AO Clock and Reset controller driver")
Suggested-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Yixun Lan <yixun.lan@amlogic.com>
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>