D27741: Convert license statements to SPDX expressions

[Andreas Cord-Landwehr]

cordlandwehr added a task: T11550: Add SPDX License markers.

REPOSITORY
  R270 KCodecs

REVISION DETAIL
  https://phabricator.kde.org/D27741

To: cordlandwehr
Cc: kde-frameworks-devel, LeGast00n, cblack, GB_2, michaelh, ngraham, bruns