power_supply: EXPORT_SYMBOL cleanups

While I'm at it, cleanup the power supply code so that EXPORT_SYMBOL_GPL
appears directly after the symbole declaration. checkpatch.pl wants it
that way.

Signed-off-by: Daniel Mack <daniel@caiaq.de>
Cc: Ian Molton <spyro@f2s.com>
Cc: Matt Reimer <mreimer@vpop.net>
Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.com>