thunderbolt: Make tb_port_get_link_speed() available to other files

We need to call this from tb.c when we improve the bandwidth management
to take USB3 into account.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>

drivers/thunderbolt/switch.c

@@ -911,7 +911,13 @@ struct tb_port *tb_next_port_on_path(struct tb_port *start, struct tb_port *end,
 	return next != prev ? next : NULL;
 }
 
-static int tb_port_get_link_speed(struct tb_port *port)
+/**
+ * tb_port_get_link_speed() - Get current link speed
+ * @port: Port to check (USB4 or CIO)
+ *
+ * Returns link speed in Gb/s or negative errno in case of failure.
+ */
+int tb_port_get_link_speed(struct tb_port *port)
 {
 	u32 val, speed;
 	int ret;

drivers/thunderbolt/tb.h

@@ -759,6 +759,8 @@ struct tb_port *tb_next_port_on_path(struct tb_port *start, struct tb_port *end,
 	for ((p) = tb_next_port_on_path((src), (dst), NULL); (p);	\
 	     (p) = tb_next_port_on_path((src), (dst), (p)))
 
+int tb_port_get_link_speed(struct tb_port *port);
+
 int tb_switch_find_vse_cap(struct tb_switch *sw, enum tb_switch_vse_cap vsec);
 int tb_switch_find_cap(struct tb_switch *sw, enum tb_switch_cap cap);
 int tb_port_find_cap(struct tb_port *port, enum tb_port_cap cap);