Disable Dynamic Crop option

[limi]

Turns out, the 1080p vadjustfile is applied even though you are not in a 1080p resolution. So to support other resolutions, we should offer an option to disable the Dynamic Crop 1080p/4K scaling.

There used to be a check like this:

if NOT EXISTS ENV:dsblvadj

And the scripts to disable/enable looked like this

echo "1" >ENV:dsblvadj
echo "1" >ENVARC:dsblvadj

and

delete ENV:dsblvadj >NIL:
delete ENVARC:dsblvadj >NIL:

They also applied a default crop, but in a way that is not compatible with the current way that is handled.

We would also need to kill the vadjust file in MiSTer: if it exists.