drm/i915/display: use DISPLAY_VER() on remaining users

Commit 989634fb ("drm/i915/audio: set HDA link parameters in driver")
added INTEL_GEN() in the display code, where it should actually be using
DISPLAY_VER(). Switch to the new macro.

Cc: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210413051002.92589-2-lucas.demarchi@intel.com

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

@@ -1309,7 +1309,7 @@ static void i915_audio_component_init(struct drm_i915_private *dev_priv)
 	if (DISPLAY_VER(dev_priv) >= 9) {
 		aud_freq_init = intel_de_read(dev_priv, AUD_FREQ_CNTRL);
 
-		if (INTEL_GEN(dev_priv) >= 12)
+		if (DISPLAY_VER(dev_priv) >= 12)
 			aud_freq = AUD_FREQ_GEN12;
 		else
 			aud_freq = aud_freq_init;