The method ImpGetBitmapEx in svdhdl.cxx needs special single
marker files to generate display dependent markers on the fly.
List them in bitmaps.hlst so that they are packed and delivered.

Change-Id: I26d86fa31d82ab623016c9ed0bfb6eb9a3e91a14
Reviewed-on: https://gerrit.libreoffice.org/62488
Tested-by: Jenkins
Reviewed-by: Tomaž Vajngerl <quikee@gmail.com>