During the previous |struct clk| to |struct clk_hw| clk provider API
migration in commit 6f691a586296 ("clk: mediatek: Switch to clk_hw
provider APIs"), a few clk_unregister_*() calls were missed.
Migrate the remaining ones to the |struct clk_hw| provider API, i.e.
change clk_unregister_*() to clk_hw_unregister_*().
Fixes: 6f691a586296 ("clk: mediatek: Switch to clk_hw provider APIs")
Signed-off-by: Chen-Yu Tsai <wenst@xxxxxxxxxxxx>