bridge: cfm: Add BRIDGE_CFM to Kconfig.

This makes it possible to include or exclude the CFM
protocol according to 802.1Q section 12.14.

Signed-off-by: Henrik Bjoernlund <[e-mail]>
Reviewed-by: Horatiu Vultur <[e-mail]>
Acked-by: Nikolay Aleksandrov <[e-mail]>
Signed-off-by: Jakub Kicinski <[e-mail]>

net/bridge/Kconfig

···
 	  Say N to exclude this support and reduce the binary size.
 
 	  If unsure, say N.
+
+config BRIDGE_CFM
+	bool "CFM protocol"
+	depends on BRIDGE
+	help
+	  If you say Y here, then the Ethernet bridge will be able to run CFM
+	  protocol according to 802.1Q section 12.14
+
+	  Say N to exclude this support and reduce the binary size.
+
+	  If unsure, say N.

net/bridge/br_device.c

···
 #if IS_ENABLED(CONFIG_BRIDGE_MRP)
 	INIT_LIST_HEAD(&br->mrp_list);
 #endif
+#if IS_ENABLED(CONFIG_BRIDGE_CFM)
+	INIT_HLIST_HEAD(&br->mep_list);
+#endif
 	spin_lock_init(&br->hash_lock);
 
 	br->bridge_id.prio[0] = 0x80;

net/bridge/br_private.h

···
 #if IS_ENABLED(CONFIG_BRIDGE_MRP)
 	struct list_head		mrp_list;
 #endif
+#if IS_ENABLED(CONFIG_BRIDGE_CFM)
+	struct hlist_head		mep_list;
+#endif
 };
 
 struct br_input_skb_cb {