thermal: add description for integral_cutoff unit

Add more explicitly description for unit of integral_cutoff which used
by power allocator governor.

Signed-off-by: Leo Yan <leo.yan@linaro.org>
Acked-by: Javi Merino <javi.merino@arm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
1 file changed