transport: add transport_is_hla()

and move declaration of all transport_is_xxx() functions to transport.h

Change-Id: Ib229115b5017507b49655bc43b517ab6fb32f7a6
Signed-off-by: Tomas Vanek <vanekt@fbl.cz>
Reviewed-on: http://openocd.zylin.com/4469
Tested-by: jenkins
Reviewed-by: Matthias Welwarsky <matthias@welwarsky.de>

src/jtag/hla/hla_transport.c

@@ -233,3 +233,11 @@ static void hl_constructor(void)
 	transport_register(&hl_jtag_transport);
 	transport_register(&stlink_swim_transport);
 }
+
+bool transport_is_hla(void)
+{
+	struct transport *t;
+	t = get_current_transport();
+	return t == &hl_swd_transport || t == &hl_jtag_transport
+		   || t == &stlink_swim_transport;
+}