thunderbolt: Move struct tb_cap_any to tb_regs.h

This structure will be needed by the debugfs implementation so make it
available outside of cap.c.

While there add kernel-doc comments to the structure.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/thunderbolt/cap.c

@@ -15,14 +15,6 @@
 #define VSE_CAP_OFFSET_MAX	0xffff
 #define TMU_ACCESS_EN		BIT(20)
 
-struct tb_cap_any {
-	union {
-		struct tb_cap_basic basic;
-		struct tb_cap_extended_short extended_short;
-		struct tb_cap_extended_long extended_long;
-	};
-} __packed;
-
 static int tb_port_enable_tmu(struct tb_port *port, bool enable)
 {
 	struct tb_switch *sw = port->sw;

drivers/thunderbolt/tb_regs.h

@@ -93,6 +93,20 @@ struct tb_cap_extended_long {
 	u16 length;
 } __packed;
 
+/**
+ * struct tb_cap_any - Structure capable of hold every capability
+ * @basic: Basic capability
+ * @extended_short: Vendor specific capability
+ * @extended_long: Vendor specific extended capability
+ */
+struct tb_cap_any {
+	union {
+		struct tb_cap_basic basic;
+		struct tb_cap_extended_short extended_short;
+		struct tb_cap_extended_long extended_long;
+	};
+} __packed;
+
 /* capabilities */
 
 struct tb_cap_link_controller {