drm/i915: Simplify has_sagv function

The specially case for SKL for not controlled sagv
is already taken care inside intel_enable_sagv, so there's
no need to duplicate the check here.

v2: Go one step further and remove skl special case. (Jani)
v3: Separate runtime status handle from has_sagv flag.
v4: Go back and accept simple Jani proposed solution.
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181026200317.21726-1-rodrigo.vivi@intel.com

drivers/gpu/drm/i915/intel_pm.c

@@ -3611,15 +3611,8 @@ static bool skl_needs_memory_bw_wa(struct intel_atomic_state *state)
 static bool
 intel_has_sagv(struct drm_i915_private *dev_priv)
 {
-	if (IS_KABYLAKE(dev_priv) || IS_COFFEELAKE(dev_priv) ||
-	    IS_CANNONLAKE(dev_priv) || IS_ICELAKE(dev_priv))
-		return true;
-
-	if (IS_SKYLAKE(dev_priv) &&
-	    dev_priv->sagv_status != I915_SAGV_NOT_CONTROLLED)
-		return true;
-
-	return false;
+	return (IS_GEN9_BC(dev_priv) || INTEL_GEN(dev_priv) >= 10) &&
+		dev_priv->sagv_status != I915_SAGV_NOT_CONTROLLED;
 }
 
 /*