drm/i915: Do not hardcode s_max, ss_max and eu_mask for BXT

We can calculate BXT values correctly from GFX fuse values without
hardcoding special limits.

Cc: Imre Deak <imre.deak@intel.com>
Cc: Matthew D Roper <matthew.d.roper@intel.com>
Signed-off-by: Dongwon Kim <dongwon.kim@intel.com>
Reviewed-by: Arun Siluvery <arun.siluvery@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_dma.c

@@ -631,17 +631,6 @@ static void gen9_sseu_info_init(struct drm_device *dev)
 	u32 fuse2, s_enable, ss_disable, eu_disable;
 	u8 eu_mask = 0xff;
 
-	/*
-	 * BXT has a single slice. BXT also has at most 6 EU per subslice,
-	 * and therefore only the lowest 6 bits of the 8-bit EU disable
-	 * fields are valid.
-	*/
-	if (IS_BROXTON(dev)) {
-		s_max = 1;
-		eu_max = 6;
-		eu_mask = 0x3f;
-	}
-
 	info = (struct intel_device_info *)&dev_priv->info;
 	fuse2 = I915_READ(GEN8_FUSE2);
 	s_enable = (fuse2 & GEN8_F2_S_ENA_MASK) >>