sim: dv-sockser: move build to common dir

sim: dv-sockser: move build to common dir

If dv-sockser is available, lets add it to the common SIM_HW_OBJS
variable so it is always included automatically.  Now ports do not
have to shoe horn it in directly themselves.  It does mean it will
be compiled for targets that don't explicitly use it, but that's
really what we want anyways.