[][openwrt][mt7988][tool][Update smp-mt76.sh 4-RSS scenario]

[Description]
Add configurations for smp-mt76.sh to adapt to 4-RSS scenario.

If without this patch, all the RSS interrupts (4 Rx rings)
would be assigned to the same CPU.

[Release-log]
N/A


Change-Id: I60ee2b1202b0e6f5e4739137451dc9d910b11aa0
Reviewed-on: https://gerrit.mediatek.inc/c/openwrt/feeds/mtk_openwrt_feeds/+/7533272
1 file changed