board: toradex: colibri_vf: efi_loader: unset CONFIG_EFI_UNICODE_CAPITALIZATION

Unset CONFIG_EFI_UNICODE_CAPITALIZATION on boards with tough size
restrictions.

This is analogous to commit a90bf07a
("efi_loader: unset CONFIG_EFI_UNICODE_CAPITALIZATION").

Signed-off-by: Marcel Ziswiler <marcel.ziswiler@toradex.com>
Reviewed-by: Alexander Graf <agraf@suse.de>