testimage: use the new targetcontrol.py module for running tests

This patch makes the necessary changes for using the targetcontrol.py module
so that one can run the same tests on a qemu instance or a remote machine
based on the value of TEST_TARGET variable: "qemu" or "simpleremote".
The default value is "qemu" which starts a qemu instance and it's the
with what we currently have.

With "simpleremote", the remote machine must be up with network and ssh
and you need to set TEST_TARGET_IP with the IP address of the remote machine
(it can still be a qemu instance that was manually started).

Basically testimage.bbclass now does something along the lines of:
 - load tests -> deploy (prepare) / start target -> run tests.
There were a couple of changes necessary for tests and
also some cleanups/renames that were needed to adjust this change. (use
ip everywhere when refering to target and server_ip when refering to host/build machine)
Also two unnecessary and unsed methods were dropped from sshcontrol.

[ YOCTO #5554 ]

(From OE-Core rev: a7820350fa3271d78ed7476e02f4aef593be1125)

Signed-off-by: Stefan Stanacar <stefanx.stanacar@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/lib/oeqa/utils/sshcontrol.py

@@ -13,8 +13,8 @@ import select
 
 class SSHControl(object):
 
-    def __init__(self, host=None, timeout=300, logfile=None):
-        self.host = host
+    def __init__(self, ip=None, timeout=300, logfile=None):
+        self.ip = ip
         self.timeout = timeout
         self._starttime = None
         self._out = ''
@@ -35,7 +35,7 @@ class SSHControl(object):
     def _internal_run(self, cmd):
         # We need this for a proper PATH
         cmd = ". /etc/profile; " + cmd
-        command = self.ssh + [self.host, cmd]
+        command = self.ssh + [self.ip, cmd]
         self.log("[Running]$ %s" % " ".join(command))
         self._starttime = time.time()
         # ssh hangs without os.setsid
@@ -48,10 +48,10 @@ class SSHControl(object):
         if time is 0 will let cmd run until it finishes.
         Time can be passed to here or can be set per class instance."""
 
-        if self.host:
+        if self.ip:
             sshconn = self._internal_run(cmd)
         else:
-            raise Exception("Remote IP/host hasn't been set, I can't run ssh without one.")
+            raise Exception("Remote IP hasn't been set, I can't run ssh without one.")
 
         # run the command forever
         if timeout == 0:
@@ -108,15 +108,9 @@ class SSHControl(object):
         return (ret, out)
 
     def copy_to(self, localpath, remotepath):
-        actualcmd = [localpath, 'root@%s:%s' % (self.host, remotepath)]
+        actualcmd = [localpath, 'root@%s:%s' % (self.ip, remotepath)]
         return self._internal_scp(actualcmd)
 
     def copy_from(self, remotepath, localpath):
-        actualcmd = ['root@%s:%s' % (self.host, remotepath), localpath]
+        actualcmd = ['root@%s:%s' % (self.ip, remotepath), localpath]
         return self._internal_scp(actualcmd)
-
-    def get_status(self):
-        return self._ret
-
-    def get_output(self):
-        return self._out