Move get_lab_servo() from cros.servo to hosts.site_host.

In order to replace the server.cros.servo module with a client side
Servo API, it's necessary to move small amounts of content out of
the 'servo' module into other classes within autotest.  This change
moves the code for creating Servo objects for hosts in the .cros
zone from the servo module into site_host.

TEST=platform_LongPressPower on a servo DUT in the .cros lab

Change-Id: I00aabfd73fb85f15e5a2141727781d4eb58289bb
Tested-by: Richard Barnette <>
Reviewed-by: Vadim Bendebury <>
Commit-Queue: Richard Barnette <>
2 files changed