cpu/$(CPU)/Makefile.features and cpu/$(CPU)/Makefile.dep are
automatically included
Add the missing space when defining 'CPU_MODEL'.
Part of moving CPU/CPU_MODEL definition to Makefile.features to have it
available before Makefile.include.
Includes of $(CPU)/include and $(BOARD)/include and already added in the
main Makefile.include.
Verification:
There are no common headers names between boards and cpus.
Except native that has a 'periph_conf.h' in cpu instead of being in board.
