k210: Don't imply CCF

Now that the k210 clock driver does not depend on CCF, we should no longer
imply it (and probably should not have in the first place). We can also
reduce the pre-relocation malloc arena back to something sensible.

Signed-off-by: Sean Anderson <seanga2@gmail.com>
Reviewed-by: Leo Yu-Chi Liang <ycliang@andestech.com>