perf/arm-cmn: Hide XP PUB events for CMN-600

CMN-600 doesn't have XP events for the PUB channel, but we missed
the appropriate check to avoid exposing them.

Fixes: 60d15040 ("perf/arm-cmn: Support new IP features")
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/4c108d39a0513def63acccf09ab52b328f242aeb.1645727871.git.robin.murphy@arm.comSigned-off-by: Will Deacon <will@kernel.org>

drivers/perf/arm-cmn.c

@@ -595,6 +595,9 @@ static umode_t arm_cmn_event_attr_is_visible(struct kobject *kobj,
 		if ((intf & 4) && !(cmn->ports_used & BIT(intf & 3)))
 			return 0;
 
+		if (chan == 4 && cmn->model == CMN600)
+			return 0;
+
 		if ((chan == 5 && cmn->rsp_vc_num < 2) ||
 		    (chan == 6 && cmn->dat_vc_num < 2))
 			return 0;