Since commit f51a226436 ("efi_loader: provide freestanding library") in
parallel builds errors
lib/efi_selftest/../efi_loader/efi_freestanding.o:
file not recognized: File truncated
occur. Obviously make cannot correctly sequence parallel builds with a
dependency like ../efi_loader/efi_freestanding.o.
Fixes: f51a226436 ("efi_loader: provide freestanding library")
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
