Loading all_video for EFI can cause video issues in some cases since GRUB Bochs/Cirrus drivers may conflict with native EFI drivers. Change default behavior for EFI to only load EFI specific video modules. Also include a new environment variable to restore the old behavior if needed. Fixes: https://savannah.gnu.org/bugs/?66200 Signed-off-by: Andrew Hamilton <adhamilt@gmail.com> Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>