bsp: grup-efi: extend modules to match legacy config

Builtin modules used in legacy build:
https://github.com/zarhus/poky/blob/wic-plugin-pcbios-grub/scripts/lib/wic/plugins/source/bootimg-pcbios.py#L39

Modules: vga, biosdisk have not been present in the EFI build
and could not be included.

Signed-off-by: Maciej Pijanowski <maciej.pijanowski@3mdeb.com>

recipes-bsp/grub/grub-efi_%.bbappend

@@ -7,5 +7,6 @@ SRC_URI += "file://cfg"
 GRUB_BUILDIN = " \
                 boot linux ext2 fat serial part_msdos part_gpt normal \
                 efi_gop iso9660 configfile search loadenv test linux16 \
-                slaunch search_label multiboot2 \
+                slaunch search_label multiboot2 echo ls reboot chain \
+                at_keyboard \
                 "