thermal/drivers/cpufreq_cooling: Replace module.h with export.h

cpufreq_cooling cannot be modular, remove the unnecessary module.h
include and replace with export.h to handle EXPORT_SYMBOL family of
macros.

Signed-off-by: Amit Kucheria <amit.kucheria@linaro.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/7a439e41e91d8bc5ff99207f99723fcf04ca36eb.1589199124.git.amit.kucheria@linaro.org