Fix displaying OpenGL info on wayland: do not require OpenGL 3.2

Summary:
Removing the requirement of 3.2 version just fixes it for my AMD RX560 on amdgpu opensource driver, which only has 2.1 version.

Test Plan: Run kinfocenter, choose Graphical information - OpenGL tab. It should open without errors.

Reviewers: Plasma, graesslin, davidedmundson

Reviewed By: Plasma, davidedmundson

Subscribers: plasma-devel

Tags: Plasma

Differential Revision: https://phabricator.kde.org/D12003