hal/dev_io/dev_io_fe.*: add first stub for RFFE DEVIO (wip)

This is a first stub for the RFFE DEVIO and will not work!
hal/dev_io/dev_io.mk: add RFFE DEVIO to makefile

Also, some conditional compilation is in pace, in which
we can choose what DEVIOs to compile.
hal/dev_mngr/dev_mngr.mk: add conditional compilation

We can choose whether or not  we want the compilation of DEV_MNGR.
hal/hal.mk: merge all target objects
Makefile: add DEV_MNGR and DEVIO conditional compilation variables
compile.sh: add compilation script with all Makefile options