clk_div_tables are not supposed to change at runtime.
mpc512x_clk_divtable function working with const clk_div_table. So
mark the non-const structs as const.
Signed-off-by: NArvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>