For some reason the maintainers file only specifies power
supply core files.

We're surely interested in individual drivers as well, so fix
the entry.
Reported-by: NGrazvydas Ignotas <notasas@gmail.com>
Reported-by: NNeilBrown <neilb@suse.de>
Signed-off-by: NAnton Vorontsov <cbouatmailru@gmail.com>