Makefile: add new libraries targets

Now, we can specify some per-entity (dev_io, dev_mngr)
dynamic and static libraries.

Also, we had to change the libbpmclient compilation
order, as we need the static library to be compiled
before dev_io (now we depend on libbpmclient to configure
our SMIOs)

Part of the github issue #11.
hal/hal.mk: add libbpmclient.a as dev_io library

Part of the github issue #11.
hal/sm_io/*/dsp/*_exp.c: change minimum DS THRES value to 0

It makes sense to have delta-sigma minimum threshold to 0,
meaning to effectively disable this feature.

Part of the github issue #11.
examples: update examples to latest libclient API

Now, we have the option to output our debug messages
to any FILE stream. We default it to stdout.
hal/sm_io/*/swap/*: add config default function

Part of the github issue #11.
hal/sm_io/*/swap/*: registered config function to SMIO strucure

This commit closes #11 github issue.