Added GRUB modules required by mender

Makefile

@@ -36,7 +36,7 @@ grub.efi: grub-config
 	sed -i "/\/dev\/root/a \/dev\/disk\/by-label\/EFIBOOT \/boot/efi    vfat   defaults,sync,auto       0     0" /etc/fstab
 	mount /dev/$(DISK)1 /boot/efi
 	mkdir -p /boot/efi/EFI/BOOT
-	grub-mkimage -p /efi/boot -o /boot/efi/EFI/BOOT/bootx64.efi -O x86_64-efi part_gpt fat ext2 normal linux efi_gop
+	grub-mkimage -p /efi/boot -o /boot/efi/EFI/BOOT/bootx64.efi -O x86_64-efi part_gpt fat ext2 normal linux efi_gop test loadenv reboot hashsum echo halt gcry_sha256
 	@echo "$$GRUB_CONFIG" > /boot/efi/EFI/BOOT/grub.cfg
 	umount /dev/$(DISK)1
 	rm -rf grub-2.02