[][kernel][mt7988][cpu][Fix syntax error for the PMU node]

[Description]
Fix syntax error for the PMU node.

If without this patch, perf might report "cycles: PMU Hardware doesn't
support sampling/overflow-interrupts." error on the "perf record" and
"perf top" commands.

[Release-log]
N/A


Change-Id: I15392443f6f58029d569253592261e0514f51c42
Reviewed-on: https://gerrit.mediatek.inc/c/openwrt/feeds/mtk_openwrt_feeds/+/7399732
1 file changed