clk: cosmetic: reorder include files

Reorder include files in the U-Boot expected order:

the common.h header should always be first,
followed by other headers in order,
then headers with directories,
then local files.

It is a preliminary step for next patch.

Signed-off-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
Reviewed-by: Sean Anderson <seanga2@gmail.com>