srs_enb: enable console trace, use RemoteProcess class and fix params

In order for the console trace to work over SSH this commit
switches to use the default RemoteProcess class. Note that srsENB
now correctly handles the SIGHUP signal.

The commit also remove a few unneeded params of the eNB.

Change-Id: If5af43effa9145b6764a32557a20a2e1760f0486