procd: fix file permissions of /dev/tty* nodes

Signed-off-by: John Crispin <john@phrozen.org>

package/system/procd/files/hotplug.json

@@ -10,7 +10,7 @@
 					[ "if",
 						[ "or",
 							[ "eq", "DEVNAME",
-								[ "null", "full", "ptmx", "zero" ],
+								[ "null", "full", "ptmx", "zero", "tty" ],
 							],
 							[ "regex", "DEVNAME",
 								[ "^gpio", "^hvc" ],
@@ -31,6 +31,10 @@
 							[ "return" ],
 						],
 					],
+					[ "if",
+						[ "regex", "DEVNAME", "^ttyS" ],
+						[ "makedev", "/dev/%DEVNAME%", "0664" ],
+					],
 					[ "if",
 						[ "has", "DEVNAME" ],
 						[ "makedev", "/dev/%DEVNAME%", "0644" ],