automatically put TESTDATA into RESOURCES on android/ios/winrt

QFINDTESTDATA is already prepared to find it there.

Change-Id: I467392786ce6bcfbf1bd0b6079f60c9df06834b1
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@theqtcompany.com>
Reviewed-by: Oliver Wolff <oliver.wolff@theqtcompany.com>
Reviewed-by: Maurice Kalinowski <maurice.kalinowski@theqtcompany.com>