Hi had similar issue, solved copying sqldrivers folder in deploy directory.

sqldrivers contains:
libqsqlite4.a,libqsqlited4.a,qsqlite4.dll,qsqlited 4.dll.

Reason:" Most probably, the qtsqlite.dll itself depends on original SQLite DLL's which you probably need to copy as well."

On XP it is working without supplying also sqldrivers folder.