grub-efi-recipe,oniro-grub-bootconf-recipe : fusing grub-config into grub's binary .

Updating two files in a safe, transactional manner is way, way harder than updating one. By having the grub.cfg file built-into GRUB binary we can avoid a lot of complexity without limiting anything relevant. GRUB is now configured to have a built-in config file identical to the one we currently build in the oniro-grub-bootconfrecipe. And installing grub.cfg into rootfs by oniro-grub-bootconfrecipe is no longer needed.

Signed-off-by: Kareem Zarka kareem.zarka@huawei.com