Add the test configuration & timestamp frequency for Coffeelake GT2.

Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20170918112124.29541-3-lionel.g.landwerlin@intel.com