Depends on the actual build. A while ago you had to define a property o the QActions in it, nowadays it's automatic.

Hildon menus

Hildon menus are supported by Qt. qt-4.5.3-xxxx-maemo4 packages needs QActions in a "fremantle" menu. Packages with version > qt-4.5.3-xxxx-maemo4 hildonize the menu automaticall.

This and many other goodies found on

http://wiki.maemo.org/Qt4Hildon