thunderbolt: Move usb4_port_margining_caps() declaration into correct place

It is supposed to be close with the other lane margining functions so
move it there. No functional changes.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>

drivers/thunderbolt/tb.h

@@ -1327,12 +1327,12 @@ int usb4_port_router_offline(struct tb_port *port);
 int usb4_port_router_online(struct tb_port *port);
 int usb4_port_enumerate_retimers(struct tb_port *port);
 bool usb4_port_clx_supported(struct tb_port *port);
-int usb4_port_margining_caps(struct tb_port *port, u32 *caps);
 
 bool usb4_port_asym_supported(struct tb_port *port);
 int usb4_port_asym_set_link_width(struct tb_port *port, enum tb_link_width width);
 int usb4_port_asym_start(struct tb_port *port);
 
+int usb4_port_margining_caps(struct tb_port *port, u32 *caps);
 int usb4_port_hw_margin(struct tb_port *port, unsigned int lanes,
 			unsigned int ber_level, bool timing, bool right_high,
 			u32 *results);