procd: assign /dev/tty* nodes to "tty" group

Adjust default permissions and ownership of /dev/tty* nodes from
0600/root:root to 0660/root:tty in order to support granting
unprivileged user access when needed.

Signed-off-by: Jo-Philipp Wich <jo@mein.io>

package/system/procd/Makefile

@@ -8,7 +8,7 @@
 include $(TOPDIR)/rules.mk
 
 PKG_NAME:=procd
-PKG_RELEASE:=1
+PKG_RELEASE:=2
 
 PKG_SOURCE_PROTO:=git
 PKG_SOURCE_URL=$(LEDE_GIT)/project/procd.git

package/system/procd/files/hotplug.json

@@ -20,6 +20,10 @@
 						[ "regex", "DEVNAME", "^snd" ],
 						[ "makedev", "/dev/%DEVNAME%", "0660", "audio" ],
 					],
+					[ "if",
+						[ "regex", "DEVNAME", "^tty" ],
+						[ "makedev", "/dev/%DEVNAME%", "0660", "tty" ],
+					],
 					[ "if",
 						[ "has", "DEVNAME" ],
 						[ "makedev", "/dev/%DEVNAME%", "0600" ],