tdf#91650 add missing small freeze pane icon

Change-Id: If7149c29cca107661d93d6d0c0925c76f956b356
Reviewed-on: https://gerrit.libreoffice.org/15981Reviewed-by: Yousuf Philips <philipz85@hotmail.com>
Tested-by: Yousuf Philips <philipz85@hotmail.com>
(cherry picked from commit b9326330)
Reviewed-on: https://gerrit.libreoffice.org/15982Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Joren De Cuyper <jorendc@libreoffice.org>