radeon: Refer to Debian wiki page when aborting probe due to missing firmware

debian/patches/debian/firmware_class-refer-to-debian-wiki-firmware-page.patch

@@ -26,3 +26,13 @@ do this once per boot.
  
  	return rc;
  }
+--- a/drivers/gpu/drm/radeon/radeon_drv.c
++++ b/drivers/gpu/drm/radeon/radeon_drv.c
+@@ -367,6 +367,7 @@ static int radeon_pci_probe(struct pci_d
+ 	if ((ent->driver_data & RADEON_FAMILY_MASK) >= CHIP_R600 &&
+ 	    !radeon_firmware_installed()) {
+ 		DRM_ERROR("radeon kernel modesetting for R600 or later requires firmware installed\n");
++		pr_err_once("See https://wiki.debian.org/Firmware for information about missing firmware\n");
+ 		return -ENODEV;
+ 	}
+ 

debian/patches/series

@@ -15,9 +15,9 @@ debian/tools-perf-install.patch
 features/all/drivers-media-dvb-usb-af9005-request_firmware.patch
 debian/iwlwifi-do-not-request-unreleased-firmware.patch
 bugfix/all/firmware_class-log-every-success-and-failure.patch
-debian/firmware_class-refer-to-debian-wiki-firmware-page.patch
 bugfix/all/firmware-remove-redundant-log-messages-from-drivers.patch
 bugfix/all/radeon-firmware-is-required-for-drm-and-kms-on-r600-onward.patch
+debian/firmware_class-refer-to-debian-wiki-firmware-page.patch
 
 # Patches from aufs4 repository, imported with
 # debian/patches/features/all/aufs4/gen-patch.  These are only the