hal/debug/debug_subsys.*: add const qualifier to structure

This is preferred as this structure is only for internal
usage
hal/dev_io/dev_io.c: change debug message to uppercase
hal/hal_utils/dispatch_table.c: fix trivial comment typo
hal/dev_mngr/*: add new structure to monitor DEVIOs intances

This is the first step into making the dev_mngr a real
monitoring process.

This is the first patch towards the solution of
github issue #1
hal/dev_mngr/*: add new methods for spawning DEVIOs instances

Also, a few wrappers and trivial fixes were made.
Now, on dev_mngr initialization we scan the /dev
directory for our devices (/dev/fpga%d) and fill
the dev_info structures. After this, we can monitor
and spawn all of the DEVIOs that are not initialized.

This is another step in fixing the github issue #1.
hal/dev_mngr/dev_mngr.c: use new methods for spawning DEVIOs

Part of the fix of github issue #1.
hal/ll_io/*: add utility functions for LLIO

This functions are used by both dev_io and dev_mngr
to convert to/from LLIO type string and LLIO type
enumeration.

This was supposed to be committed before commits
1381e8c, c67c9829 and 006465e3.
hal/dev_io/dev_io_core.c: print nicer init messages
hal/dev_io/dev_io.c: use LLIO utility functions
hal/hal.mk: add LLIO utility file to HAL Makefile
init.sh: remove sending of SIGUSR1 signal

Now, we have a better approch to initializing
DEVIOs abnd we don't need to emulate some PCIe
signal to dev_mngr.

This fixes #1 github issue.