[autotest] Allow autoserv to start servod with given board and port from dut.

BUG=chrome-os-partner:40890
TEST=update the code and global config, run autoserv in moblab
/usr/local/autotest/server/autoserv -p  -N -m 192.168.231.101 -u debug -l \
wolf-release/R45-7263.0.0/faft_bios/firmware_EventLog -s \
-P 206-moblab/192.168.231.101 -n /usr/local/autotest/results/drone_tmp/attach.14

Change-Id: I6bd0f1211aaafd0e5ea1331354034d2b5038e06c
Reviewed-on: https://chromium-review.googlesource.com/297546
Commit-Ready: Dan Shi <dshi@chromium.org>
Tested-by: Dan Shi <dshi@chromium.org>
Reviewed-by: Dan Shi <dshi@chromium.org>
diff --git a/moblab_config.ini b/moblab_config.ini
index 1707691..720f862 100644
--- a/moblab_config.ini
+++ b/moblab_config.ini
@@ -10,3 +10,6 @@
 
 [SCHEDULER]
 minimum_tick_sec: 5
+
+[AUTOSERV]
+auto_start_servod: True