clk/actions/owl-factor.c: remove superfluous headers

clk/actions/owl-factor.c: remove superfluous headers

owl-factor.c hasn't use any macro or function declared in linux/slab.h.
Thus, these files can be removed from owl-factor.c safely without
affecting the compilation of the ./drivers/clk module

Signed-off-by: Mianhan Liu <liumh1@shanghaitech.edu.cn>
Link: https://lore.kernel.org/r/20210929065824.23691-1-liumh1@shanghaitech.edu.cn
Reviewed-by: Manivannan Sadhasivam <mani@kernel.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>