drm/i915: Do not initialize display BW when display not available

When display is not available, finding the memory bandwidth available
for display is not useful. Skip this sequence here.

References: HSDES 1209978255
Signed-off-by: Stuart Summers <stuart.summers@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191120011016.18049-1-stuart.summers@intel.com

drivers/gpu/drm/i915/display/intel_bw.c

@@ -264,6 +264,9 @@ static unsigned int icl_max_bw(struct drm_i915_private *dev_priv,
 
 void intel_bw_init_hw(struct drm_i915_private *dev_priv)
 {
+	if (!HAS_DISPLAY(dev_priv))
+		return;
+
 	if (IS_GEN(dev_priv, 12))
 		icl_get_bw_info(dev_priv, &tgl_sa_info);
 	else if (IS_GEN(dev_priv, 11))