Accroding to #9947 and #9424, adding doxygen comment for function in .c files and data structure, macro in .h file is a solution.For this pr, I encountered problem following situations.
- rt_clk_unprepare function return value type is different from rt_clk_ops so I change type of rt_clk_unprepare and its dependencies.
- clk_get function may be similar as rt_clk_unprepare but I'm not sure so not modify.
- clk_release implements may be incomplete, so I just marked in comment.
Signed-off-by: 1078249029 <1078249029@qq.com>