Support frame buffers that are larger than the default screen
size as defined by VT_FB_DEFAULT_WIDTH and VT_FB_DEFAULT_HEIGHT
(at this time 2048x1200). The default is really a max. We cap
the height and width to those defaults and position the screen
in the center of the frame buffer.

Ideally we use a bigger font to utility the entire real estate
that is the frame buffer, but that's seen as an improvement over
making it work first.

PR: 193745