thermal/core: Get rid of MODULE_* tags

The thermal framework can no longer be compiled as a module as of
commit 554b3529 ("thermal/drivers/core: Remove the module Kconfig's
option"). Remove the MODULE_* tags.

Rui is mentioned in the copyright line at the top of the file and the
license is mentioned in the SPDX tags. So no loss of information.

Signed-off-by: Amit Kucheria <amit.kucheria@linaro.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/74339a09a55f8f3d86c4074fc2bf853a302d6186.1589199124.git.amit.kucheria@linaro.org