tools/power/cpupower/{ToDo => TODO}: Rename the todo file

Renamed the to-do file to 'TODO' instead of 'ToDo' to
comply with the naming standard.

Signed-off-by: ozkanonur <onurozkan.dev@gmail.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

diff --git a/tools/power/cpupower/ToDo b/tools/power/cpupower/TODO
similarity index 100%
rename from tools/power/cpupower/ToDo
rename to tools/power/cpupower/TODO