pid_controller: add a name to the class
pid_controller: add a name to the class

Classes derived from Base should have a name, which should match with
the name in the run class.

Change-Id: I17ad56dbd4c262be0f72ca51491ba415a2e0a39b
Signed-off-by: Javi Merino <cc0c468e3dcd5ee425259d298d905a60f8330bcf@arm.com>

joelagnel/trappy,JaviMerino/trappy,derkling/trappy,JaviMerino/trappy,bjackman/trappy,bjackman/trappy,ARM-software/trappy,bjackman/trappy,sinkap/trappy,bjackman/trappy,joelagnel/trappy,derkling/trappy,ARM-software/trappy,ARM-software/trappy,sinkap/trappy,sinkap/trappy,joelagnel/trappy,JaviMerino/trappy,sinkap/trappy,joelagnel/trappy,ARM-software/trappy,derkling/trappy