drm/i915/cfl: Introduce Coffee Lake platform definition.

Coffee Lake is a IntelĀ® Processor containing IntelĀ® HD Graphics
following Kabylake.

It is Gen9 graphics based platform on top of CNP PCH.

Let's start by adding the platform definition based on previous
platforms but yet as preliminary_hw_support.

On following patches we will start adding PCI IDs and the
platform specific changes.

v2: Also add BS2 ring that is present on GT3. As on KBL, according
    spec: "GT3 also has additional media blocks with second instance
    of VEBox and VDBox each", i.e. BSD2 ring in our case. Noticed
    when reviewing PCI ID patches.

v3: CFL_PLATFORM instead for CFL_FEATURES because it contains
    Platform information and no new features when compared to
    BDW_FEATURES definition.

v4: Rebased on top of Cannonlake patches.

Cc: Anusha Srivatsa <anusha.srivatsa@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Anusha Srivatsa <anusha.srivatsa@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1496937000-8450-1-git-send-email-rodrigo.vivi@intel.com
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index f9632ea..dd22f3d 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -825,6 +825,7 @@ enum intel_platform {
 	INTEL_BROXTON,
 	INTEL_KABYLAKE,
 	INTEL_GEMINILAKE,
+	INTEL_COFFEELAKE,
 	INTEL_CANNONLAKE,
 	INTEL_MAX_PLATFORMS
 };
@@ -2768,6 +2769,7 @@ intel_info(const struct drm_i915_private *dev_priv)
 #define IS_BROXTON(dev_priv)	((dev_priv)->info.platform == INTEL_BROXTON)
 #define IS_KABYLAKE(dev_priv)	((dev_priv)->info.platform == INTEL_KABYLAKE)
 #define IS_GEMINILAKE(dev_priv)	((dev_priv)->info.platform == INTEL_GEMINILAKE)
+#define IS_COFFEELAKE(dev_priv)	((dev_priv)->info.platform == INTEL_COFFEELAKE)
 #define IS_CANNONLAKE(dev_priv)	((dev_priv)->info.platform == INTEL_CANNONLAKE)
 #define IS_MOBILE(dev_priv)	((dev_priv)->info.is_mobile)
 #define IS_HSW_EARLY_SDV(dev_priv) (IS_HASWELL(dev_priv) && \