thermal/drivers/clock_cooling: Sort headers alphabetically

Sort headers to make it easier to read and find duplicate headers.

Signed-off-by: Amit Kucheria <amit.kucheria@linaro.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/f8e1258fd8b882bab018de63c7e713b4334fec30.1589199124.git.amit.kucheria@linaro.org