thermal/drivers/cpufreq_cooling: Fix wrong frequency converted from power

The function cpu_power_to_freq is used to find a frequency and set the
cooling device to consume at most the power to be converted. For example,
if the power to be converted is 80mW, and the em table is as follow.
struct em_cap_state table[] = {
	/* KHz     mW */
	{ 1008000, 36, 0 },
	{ 1200000, 49, 0 },
	{ 1296000, 59, 0 },
	{ 1416000, 72, 0 },
	{ 1512000, 86, 0 },
};
The target frequency should be 1416000KHz, not 1512000KHz.

Fixes: 349d39dc ("thermal: cpu_cooling: merge frequency and power tables")
Cc: <stable@vger.kernel.org> # v4.13+
Signed-off-by: Finley Xiao <finley.xiao@rock-chips.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20200619090825.32747-1-finley.xiao@rock-chips.com