Add .prf.in files to OTHER_FILES
Add .prf.in files to OTHER_FILES

RevBy: TrustMe
Makes them show up in Qt Creator.

Full, original commit at 1667910756de75e467cba709abc0dbe207b3739d in maliit-framework

maliit/inputcontext-qt4,perencia/inputcontext-qt4,maliit/inputcontext-qt4