Broken compatibility with compilers that do not support std::make_unique

Commit f55e6054f0 added std::make_unique to /qtdeclarative/src/quick/items/qquickgridview.cpp and /qtdeclarative/src/quick/items/qquicklistview.cpp, causing incompatibility with compilers that do not support it. To fix this, I am attaching a patch that will add include private/qmemory_p.h to these files and replace std::make_unique with qt_make_unique.