remove hex and eep targets
remove hex and eep targets

the hex and eep targets are not applicable to the Userspace.mk,
removing them and setting the default target as elf.

bugobliterator/BUAGI,bugobliterator/BUAGI,bugobliterator/BUAGI,prpplague/Userspace-Arduino,prpplague/Userspace-Arduino,bugobliterator/BUAGI,bugobliterator/BUAGI,prpplague/Userspace-Arduino,bugobliterator/BUAGI,prpplague/Userspace-Arduino