If SPL_CLK_IMX8MP is selected alone, it causes a build error.
The clock composite is required when using the clock framework, so
select it when SPL_CLK_IMX8MP is enabled. This is already being
done outside of SPL.
Signed-off-by: Adam Ford <aford173@gmail.com> Reviewed-by: Peng Fan <peng.fan@nxp.com>