Add device selection in IGT

New IGT command line argument --device, IGT_DEVICE enviroment and .igtrc
Common::Device were added to allow selecting device using device
selection API. See generated docs for device selection and lsgpu for
more details on filters.

NOTE: IGT_FORCE_DRIVER still works if no filter is selected. We may want
      to deprecate it later.

NOTE2: This does not work with tests that open 2 or more devices (e.g.
       kms_prime). The core is capable of doing multiple filtering
       passes but we need to figure out how we want *open*() functions
       to expose this capability.

v2 (Arek):
 * remove functions acting on igt_device_card
 * use only a single filter
v3 (Arek):
 * typos, misspellings (Petri)
 * add notes on IGT_FORCE_DRIVER and opening 2 or more devices

Cc: Petri Latvala <petri.latvala@intel.com>
Signed-off-by: Zbigniew Kempczyński <zbigniew.kempczynski@intel.com>
Signed-off-by: Arkadiusz Hiler <arkadiusz.hiler@intel.com>
Reviewed-by: Petri Latvala <petri.latvala@intel.com>