sh: clkfwk: modify for_each_frequency end condition

The end condition of for_each_frequency should care about
both clk_rate_table_round and clk_rate_div_range_round,
and using "correct max size" is a natural idea in later function.
To avoid data over flow, this patch didn't modify
clk_rate_div_range_round side as .max = div_max + 1.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>