vcl: remove IOS/OSX only code

Change-Id: I83fd835a8a198ff469cfaa0441c938acf9433862
Reviewed-on: https://gerrit.libreoffice.org/13206
Reviewed-by: Chris Sherlock <chris.sherlock79@gmail.com>
Tested-by: Chris Sherlock <chris.sherlock79@gmail.com>