drm/i915/display: Add write permissions for fec support

Though there is a write option available on  fec_suport
debugfs file, so far it has been registering with read
permissions only.
Suggested-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Vandita Kulkarni <vandita.kulkarni@intel.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210720064907.9771-2-vandita.kulkarni@intel.com

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

@@ -2434,7 +2434,7 @@ int intel_connector_debugfs_add(struct drm_connector *connector)
 	}
 
 	if ((DISPLAY_VER(dev_priv) >= 11 || IS_CANNONLAKE(dev_priv)) && ((connector->connector_type == DRM_MODE_CONNECTOR_DisplayPort && !to_intel_connector(connector)->mst_port) || connector->connector_type == DRM_MODE_CONNECTOR_eDP))
-		debugfs_create_file("i915_dsc_fec_support", S_IRUGO, root,
+		debugfs_create_file("i915_dsc_fec_support", 0644, root,
 				    connector, &i915_dsc_fec_support_fops);
 
 	/* Legacy panels doesn't lpsp on any platform */