Run gnu-efi/Makefile every time? #798

I'm learning to build a uefi netboot program recently, and tried to make some modifications inside gnu-efi. But make doesn't rebuild gnu-efi at all. After doing some rearch, i found gnu-efi will not being built when gnu-efi/$(ARCH_GNUEFI)/gnuefi/libgnuefi.a and gnu-efi/$(ARCH_GNUEFI)/lib/libefi.a exist. So could you consider to make the gnu-efi/Makefile script being run every time shim's Makefile is run to keep gnu-efi up to date?