BACKPORT: thermal/drivers/hisi: Convert long to int

There is no point to specify the temperature as long variable, the int is
enough.

Replace all long variables to int, so making the code consistent.

Change-Id: Iabed1d48fa61963bb2ef7ec13b018970fe96cff6
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Leo Yan <leo.yan@linaro.org>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
(cherry picked from commit bc02ef6d98a601a39f735cbbb67807fb752b5138)
Signed-off-by: Kevin Wangtao <kevin.wangtao@hisilicon.com>