taprio: Add support for cycle-time-extension

IEEE 802.1Q-2018 defines the concept of a cycle-time-extension, so the
last entry of a schedule before the start of a new schedule can be
extended, so "too-short" entries can be avoided.

Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/uapi/linux/pkt_sched.h

@@ -1168,6 +1168,7 @@ enum {
 	TCA_TAPRIO_PAD,
 	TCA_TAPRIO_ATTR_ADMIN_SCHED, /* The admin sched, only used in dump */
 	TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME, /* s64 */
+	TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME_EXTENSION, /* s64 */
 	__TCA_TAPRIO_ATTR_MAX,
 };