sched: energy: Remove #define DEBUG

Production kernels should not be printing debug level logging.
Remove #define DEBUG from energy.c. Convert a an appropriately
small subset of messages into _info - these are printed just
once during boot and convey important device information that
can save a lot of teams and customers a lot of effort.

Change-Id: Idd0bb043b65c302682baa84057bb7cd55c10b425
Signed-off-by: Vikram Mulukutla <markivx@codeaurora.org>