rtos: Support rt-kernel

Works for the proprietary rt-kernel from rt-labs.

See: https://rt-labs.com/product/rt-kernel/
Change-Id: Id2c2e292c15fb17eab25e3d07db05014daa2a2b0
Signed-off-by: Andreas Fritiofson <andreas.fritiofson@gmail.com>
Reviewed-on: https://review.openocd.org/c/openocd/+/6668
Tested-by: jenkins
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>

src/rtos/rtos.c

@@ -29,6 +29,7 @@ extern struct rtos_type nuttx_rtos;
 extern struct rtos_type hwthread_rtos;
 extern struct rtos_type riot_rtos;
 extern struct rtos_type zephyr_rtos;
+extern struct rtos_type rtkernel_rtos;
 
 static struct rtos_type *rtos_types[] = {
 	&threadx_rtos,
@@ -43,6 +44,7 @@ static struct rtos_type *rtos_types[] = {
 	&nuttx_rtos,
 	&riot_rtos,
 	&zephyr_rtos,
+	&rtkernel_rtos,
 	/* keep this as last, as it always matches with rtos auto */
 	&hwthread_rtos,
 	NULL