Support DVI settings from RP2040/PIO version of picodvi in the RP2350/HSTX version

[RetiredWizard]

In order to run the Demo program from the Adafruit DVI Sock learn guide using a Pico2, the picodvi Framebuffer dimensions need to be changed from 320x240 to 640x480, however with that change the larger framebuffer uses a lot more RAM so even with the additional resources of the Pico2 the demo won't run unless the color_depth is cut from 8 to 4.

If the RP2350 version of picodvi could support the older 320x240 in addition to the 640x480 resolution, that would allow the Pico2 to be a drop in replacement for the Pico when using the DVI Sock and enable more memory intensive use cases with deeper color depths.

[tannewt]

I think we can set this up to work. It is a good point that the demo should port over.