[b2qt] Toradex Colibri VF image should switch to kms driver usage

The latest 5.7.0-2 Toradex Colibri VF image switches blue and red colors with LCD screen EDT 5.7".

Comment from Toradex on this issue:

The problem is likely due to switch to the DRM/KMS driver in our V2.6 release. In V2.5, we used a fbdev only driver.

The V2.6 release still offers fbdev access through fbdev emulation. However, it could be that the default configuration is now a bit different (maybe 24-bit vs 16-bit colors...). In our default image we do not see issues, but we also don't use the fbdev interface (we use the X.org modesetting driver which uses the DRM/KMS interface directly).