D11360: provide sample rate in kHz

[Nathaniel Graham]

ngraham added a reviewer: Baloo.

REPOSITORY
  R824 Baloo Widgets

REVISION DETAIL
  https://phabricator.kde.org/D11360

To: astippich, #frameworks, #baloo
Cc: elvisangelaccio, ashaposhnikov, astippich, spoorun, nicolasfella, alexeymin