vidmode: Let the driver resize the framebuffer when switching modes

Resize the framebuffer when switching modes with VidMode. This allows
better interaction with randr, which may have shrunk the framebuffer
when changing to a smaller mode.
2 jobs from vidmode-resize-fb in 2 minutes and 5 seconds (queued for 1 second)
latest
Status Job ID Name Coverage
  Docker Image
passed #89668
debian-testing

00:00:31

 
  Build And Test
passed #89669
build-and-test

00:01:33