drm/i915: whitelist PS_(DEPTH|INVOCATION)_COUNT

CFL:C0+ changed the status of those registers which are now
blacklisted by default.

This is breaking a number of CTS tests on GL & Vulkan :

  KHR-GL45.pipeline_statistics_query_tests_ARB.functional_fragment_shader_invocations (GL)

  dEQP-VK.query_pool.statistics_query.fragment_shader_invocations.* (Vulkan)

v2: Only use one whitelist entry (Lionel)

Bspec: 14091
Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Cc: stable@vger.kernel.org # 6883eab27481: drm/i915: Support flags in whitlist WAs
Cc: stable@vger.kernel.org
Acked-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20190628120720.21682-3-lionel.g.landwerlin@intel.com
(cherry picked from commit 2c903da5

)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>