drm/i915: Extract hsw_panel_transcoders()

Extract the "panel transcoder" bitmask into a helper. We'll
have a couple of uses for this later.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210913144440.23008-9-ville.syrjala@linux.intel.comReviewed-by: Jani Nikula <jani.nikula@intel.com>

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

@@ -5599,21 +5599,27 @@ static bool ilk_get_pipe_config(struct intel_crtc *crtc,
 	return ret;
 }
 
+static u8 hsw_panel_transcoders(struct drm_i915_private *i915)
+{
+	u8 panel_transcoder_mask = BIT(TRANSCODER_EDP);
+
+	if (DISPLAY_VER(i915) >= 11)
+		panel_transcoder_mask |= BIT(TRANSCODER_DSI_0) | BIT(TRANSCODER_DSI_1);
+
+	return panel_transcoder_mask;
+}
+
 static bool hsw_get_transcoder_state(struct intel_crtc *crtc,
 				     struct intel_crtc_state *pipe_config,
 				     struct intel_display_power_domain_set *power_domain_set)
 {
 	struct drm_device *dev = crtc->base.dev;
 	struct drm_i915_private *dev_priv = to_i915(dev);
-	unsigned long panel_transcoder_mask = BIT(TRANSCODER_EDP);
+	u8 panel_transcoder_mask = hsw_panel_transcoders(dev_priv);
 	unsigned long enabled_panel_transcoders = 0;
 	enum transcoder panel_transcoder;
 	u32 tmp;
 
-	if (DISPLAY_VER(dev_priv) >= 11)
-		panel_transcoder_mask |=
-			BIT(TRANSCODER_DSI_0) | BIT(TRANSCODER_DSI_1);
-
 	/*
 	 * The pipe->transcoder mapping is fixed with the exception of the eDP
 	 * and DSI transcoders handled below.