thermal: cpu_cooling: standardize end of function

Just for code readiness, this patch makes all functions
on this file to have a blank line before their returns.
Now, some functions follow this pattern, and others will
not have a blank line. So, this patch makes it a single
pattern.

Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>