runner: Add --version to igt_runner

To help verify correct deployment, add a --version flag to igt_runner
that just prints the IGT-version text, the same tests would print.

Note that only igt_runner gained the --version flag. igt_resume and
igt_results don't do fancy flag handling, they only accept the
directory to operate as their single arg.

v2: Depend on version.h (CI)

Signed-off-by: Petri Latvala <petri.latvala@intel.com>
Cc: Tomi Sarvela <tomi.p.sarvela@intel.com>
Cc: Arkadiusz Hiler <arkadiusz.hiler@intel.com>
Reviewed-by: Arkadiusz Hiler <arkadiusz.hiler@intel.com>