apalis-tk1: remove default vesa vga mode from vidargs

Remove video=tegrafb0:640x480-16@60 aka VESA VGA mode from vidargs in
order for the panel specification in the device tree to be used. This
causes the default to be the 10.1" LVDS display which will be available
in the Toradex webshop shortly.

Reviewed-by: Oleksandr Suvorov <oleksandr.suvorov@toradex.com>
Signed-off-by: Marcel Ziswiler <marcel.ziswiler@toradex.com>
Signed-off-by: Igor Opaniuk <igor.opaniuk@toradex.com>
Signed-off-by: Tom Warren <twarren@nvidia.com>