...in order to support sRGB framebuffers.
Add a --srgb option to the qopenglwidget example to allow testing.
[ChangeLog][QtWidgets][QOpenGLWidget] Added support for specifying
custom internal texture formats in QOpenGLWidget in order to make it
possible to have the widget backed by an sRGB-capable framebuffer.
Task-number: QTBUG-50987
Change-Id: I112e2f0ab0b1478c69e601031aa0bafaa87fa847
Reviewed-by: Andy Nichols <andy.nichols@qt.io>