fix bootloader of addon and promo dvds
the addon and promo DVDs have a broken bootloader in UEFI mode. They only shows KDE. A custom grub2 config is needed to display entries for GNOME, KDE and install just like in legacy mode.
The DVDs can be tested in KVM by installling the tianocore firmware:
Test using qemu-kvm -L /usr/share/qemu-ovmf/bios -cdrom openSUSE-12.3-Promo-DVD-x86_64-Build*-Media.iso