drm/i915/dp: Some reshuffling in mode_valid as prep for bigjoiner modes

No functional changes. This patch just moves some mode checks
around to prepare for adding bigjoiner related mode validation

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Manasi Navare <manasi.d.navare@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201112023954.12301-1-manasi.d.navare@intel.com

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

@@ -721,6 +721,9 @@ intel_dp_mode_valid(struct drm_connector *connector,
 	if (mode->flags & DRM_MODE_FLAG_DBLSCAN)
 		return MODE_NO_DBLESCAN;
 
+	if (mode->flags & DRM_MODE_FLAG_DBLCLK)
+		return MODE_H_ILLEGAL;
+
 	if (intel_dp_is_edp(intel_dp) && fixed_mode) {
 		if (mode->hdisplay > fixed_mode->hdisplay)
 			return MODE_PANEL;
@@ -731,6 +734,9 @@ intel_dp_mode_valid(struct drm_connector *connector,
 		target_clock = fixed_mode->clock;
 	}
 
+	if (mode->clock < 10000)
+		return MODE_CLOCK_LOW;
+
 	max_link_clock = intel_dp_max_link_rate(intel_dp);
 	max_lanes = intel_dp_max_lane_count(intel_dp);
 
@@ -771,12 +777,6 @@ intel_dp_mode_valid(struct drm_connector *connector,
 	    target_clock > max_dotclk)
 		return MODE_CLOCK_HIGH;
 
-	if (mode->clock < 10000)
-		return MODE_CLOCK_LOW;
-
-	if (mode->flags & DRM_MODE_FLAG_DBLCLK)
-		return MODE_H_ILLEGAL;
-
 	status = intel_dp_mode_valid_downstream(intel_connector,
 						mode, target_clock);
 	if (status != MODE_OK)