sdvx: landscape mode messes with camera

## Game and version
sdvx eg

## Version of spice2x
25-03-29 and onwards

## Describe the issue
When landscape mode is on, camera (for the lanes) is significantly more zoomed out than usual.

It seems that the game uses backbuffer dimensions to calculate the camera.

Probably messes with various camera effects as well....

## Attached log.txt file, if available
