Wayland: add waylandgl platform type
Wayland: add waylandgl platform type

This will set mUseOpenGL when -platform waylandgl is passed to clients.

ntanibata/qtwayland,locusf/qtwayland-1,Tofee/qtwayland,locusf/qtwayland-1,locusf/qtwayland-1,ntanibata/qtwayland,Tofee/qtwayland,ntanibata/qtwayland,Tofee/qtwayland,locusf/qtwayland-1